Timbertop is a full-time boarding, co-educational campus of Geelong Grammar School located near Mansfield, Victoria, Australia.It shares its name with Mount Timbertop, which towers directly over the school.

Established in 1953, by then Headmaster James Darling, Timbertop is attended by year-nine students attending Geelong Grammar School, although there are limited spaces and not all students are able to attend. As of 2017 approximately 240 boys and girls attend Timbertop, where they are divided into single-sex 'units' of approximately 15 students. They participate in a wide variety of physical activities including running, hiking, and skiing, as well as a normal academic routine. Additionally, students at Timbertop do not have access to devices such as computers, mobile phones, or digital cameras, and external news is typically received via newspaper or radio. Almost all communication from students to family and friends off campus is carried through hand-written letters. In order for students to receive hot water for showers, cleaning and heating, they must chop their own wood, which is then placed in a boiler accompanying each unit building.

In December 1951, Geelong Grammar School announced that it had an option on a piece of land near Mount Timbertop where they would conduct normal schooling combined with outdoor activities that would foster independence and initiative. The concept was the initiative of headmaster James Darling, who was inspired by the likes of Kurt Hahn and England's Outward Bound schools.

The Timbertop campus opened at the start of the 1953 school year with 40 students who would be building sheds, paths, roads and a plantation. The campus consists of 800 hectares (2,000 acres) with a frontage onto the Delatite River.

On the 2nd February 1960, Graeme Vanner, a student who joined the main Corio campus in Geelong House (now Allen House) the year prior, then D Unit at Timbertop, drowned during a swimming test in the school's Swimming Dam on the second day of the term. He is buried in the Barrabool Hills Cemetery, in Highton, Geelong.

On 5 December 1978, the then-principal, The Hon Charles Fisher, whilst en route to Timbertop as part of a routine visit from the main campus, fell victim to fatigued driving, potentially owing to the lengthy drive between Geelong and Timbertop, and subsequently drove his car off the Maroondah Highway and crashed into a tree in Kanumbra, outside of Merton, killing him instantly. He died at the age of 57, and was cremated. A memorial service took place at the Corio Campus three days later, on 8 December 1978.

In 1996, Tim Collins, a student in G Unit, collapsed and passed away as a result of a congenital heart condition whilst on the final 6-day-long hike of Timbertop, near 'Peters Corner', the intersection of Circuit Road and an old 4WD track that leads down to King Hut, below Mount Stirling. Both Graeme Vanner and Tim Collins have since been immortalised in the form of a memorial grove of trees beneath the summit of Bald Hill which was planted in June 2024, occupying a vista on one of the most prominent geographic features on the campus.

In 2006, a large bushfire, which had not only encircled nearby Mount Buller and its ski resort, but had reached the rear of the school grounds, resulted in the entire campus being evacuated in a space of three hours. In this time of evacuation, students and staff reputedly ran up to the chapel to "bid farewell", in case the chapel were to succumb to the encroaching bushfire. No buildings were ever damaged by the bushfire.

In 2009, the Timbertop Campus was forced to evacuate to the main Geelong Grammar School Campus at Corio due to severe bushfires close to the campus.

Timbertop has an academic programme much like other schools. For five days of every week, classes take place on the Timbertop campus. Students take part in compulsory "core" classes, such as English, mathematics, science, Australian curriculum history, and positive education. Students must also choose electives from a list including German, French, Chinese, Japanese, music, physical education, elective history, geography, agriculture, and art.

The school introduced positive education to Timbertop in 2009. It is a compulsory core subject.

Timbertop has an extensive outdoors programme which encompasses hiking, downhill skiing, cross-country skiing, rogaining (a team-based orienteering sport), and camping.

Students begin with two training sessions at the start of the year, in which they are taught to use and clean trangia stoves, pitch tents, and correctly use their hiking gear. They then complete other hikes to places such as Mt. Stirling, The Bluff, and Mt. Buller, to familiarise themselves with the area, and to build up to a three-day hike, where they choose the route and its difficulty themselves. The first "Solo" session also occurs, with students spending a day by themselves in a tent on the Timbertop Campus, where they reflect, and think about goals for the year, and future life.

In term 2, students take part in a Unit Hike, but most of the term is taken up with Community Service and School Service; a second "Solo" also occurs.

In term 3, students participate in Downhill Skiing on Mt Buller, where they do lessons, and free skiing. The students also learn Cross Country Skiing on two unit based trips, on Mount Stirling, near GGS hut, and on the Bogong High Plains. At the end of the term, students take part in a unit based "Mystery Hike".

Term 4 is the culmination of the outdoors programme. Returning students participate in Option Hikes 1 and 2, which vary in difficulty depending on the choices of the hike groups. The last unit based outdoor trip is a Walk Canoe Raft, where units do some walking, canoeing, and rafting (or sledding) near William Hovell Dam. Hike Rogaine takes place towards the middle of the term. Students walk to Mt Stirling, then compete in a Rogaine on Mt Stirling. The Hiking year culminates in the Four and Six Day hikes, where students choose and design routes, and are given a large amount of autonomy in choosing where they go, distances walked, and food taken. Students then partake in their third and final "Solo".

In 2018, the final Unit trip "Walk Canoe Raft" was replaced (indefinitely) with a third Option Hike.

In total, students camp for between 50 and 55 nights during the year.

Running, and in particular trail running (given the rural and hilly location of the school) makes up a large part of the Timbertop Programme. Students run between two or three times a week depending on the term. The aim of the running programme is to build the resilience and fitness of the students, to prepare them for The Timbertop Marathon, and ultimately later life.

"Crossies" provide a base line for fitness, and are increased incrementally every Term. The term 1 crossie is about 3 kilometres long, eventually reaching about 5 kilometres by term 4. Crossies are run every week before or after school starts (depending on term).

"Long Runs" are longer than the other runs. The length of the runs increases every week, starting (at the start of term 1) at approximately 4 km, and ending (at the end of term 4) at around 23 km, the penultimate run before the Marathon. This run involves running up West Ridge to the summit of Mt Buller and back to the campus.

"Wildfire Crossies" are short runs done in terms 2 and 3, designed to build fitness through interval training.

The Timbertop Running Programme builds up to Marathon at the end of term 4, which varies in length depending on the decision of staff, and available tracks to run, but is generally 33 km long. Whilst the Timbertop Marathon is much shorter than a standard marathon (42.195 kilometres) it takes place on rough tracks and with hilly/mountainous terrain.

The Hobbies programme takes place in Term 3, before ski days. Students select two hobbies from a list that includes activities including but not limited to Snowboarding, Fly Fishing, Horse Riding and Mountain Biking.

All students at Timbertop are placed in units of 14–16 people. Boys units are named A through to H, and Girls units are named I through to P, making a total of 16 units. There are both "new" and "old" units; "old" units were constructed by students in the 1950s through to the 1970s while "new" units have been slowly replacing the older buildings since 2009. As of 2021, Old units include A, B, C, E, F, H, L, M, N and O, while new units include D, G, I, J, K and P. Students sleep, clean, study, maintain, and live in their units for the year. Once a week, units perform a "Sunday inspection", which actually occur on a Tuesday despite the name. During the inspection, every part of the unit is cleaned to a high standard and inspected by the unit's Head of Unit. Additionally, students perform two inspections per normal day to maintain cleanliness and hygiene in the unit.

The units are divided into two "Schools": A School and B School. The units that compose the two schools vary by year, and as of 2021, A School is made up of A, D, E, F, I, J, K and O units, with B School being B, C, G, H, L, M, N and P units. The two schools are always completely separate classes, and elective subjects in one school take place whilst the other has core subjects.

When old unit buildings are replaced with new buildings, they are simply converted for other functions instead of being demolished and rebuilt, with replacements built elsewhere (the notable exception is G unit, which was rebuilt). In fact, many classrooms on the Timbertop campus are former unit buildings which had been relocated into new buildings.

As of 2020, the I Unit nameplate has been reallocated to a new girl's unit which was built by the end of 2019. Previously there were 9 Boys units and 7 Girls units; A through I and J through P respectively. New units also have a 16-person capacity. This reallocation was done to increase capacity for girls while maintaining capacity for boys in the long-term, and to create a 50/50 split between genders in the school.

Timbertop offers a gap year programme. Assistants, known as "gappies" (singular "gappy" or "gappie") help with tasks such as co-ordinating activities, organising skiing, helping around the farm, supervising hiking groups and assisting staff in classes, among many other things. Other than former alumni, gappies typically hail from regional Australia or the United Kingdom, but the campus has seen people from countries such as France, Germany, Canada, Japan, and others.

Notable features on the campus include:

The Agriculture Centre was established in the late 1980's, and primarily deals with cattle and sheep. The large paddocks at the entrance of the school, as well as a small parcel of land on the opposite side of Mount Buller Road, are reserved for grazing. The Agriculture Centre proper consists of several small sheds and pens, as well as an octangular-shaped classroom, reserved for students studying agriculture. Many of the buses that transport students to and from drop-off/pick-up points on their hiking journeys meet in the vicinity of this area.

Owing its name to its largely-cleared summit, Bald Hill is 644 metres in height. It is at the intersection of several frequented running routes, including Wild Dog Road (a public, unsealed road along the western approach to the hill), Blackberry Spur, which protrudes down the hill toward Mount Buller Road, and the Bald Hill Switchbacks/Face Tracks.

Formerly known as "Sheepskull Hill", Barclays Hill, at a height of 610 metres, is the closest hill to the entrance of the school. Students also run up this hill, and the summit is marked by a small fireplace. From the eastern face, the Gravel Pits track cuts along the perimeter of the campus boundary, where students must cross a wooden stile that leads them off the campus, where they reach a quarry. This region, whilst not on the campus boundary, is located at the base of Ruby's Knoll, a small hill upon which many orienteering challenges take place.

B Unit Flat is a tract of flat ground on the side of the Timbertop Creek. It gets its name from B Unit, which is the closest unit to this flat area. This space is typically reserved for camping in the earlier months of the year.

Built in stages by staff and students in 1958, the Chapel is host to several services each week. A bell adjacent to the Chapel is rung out, which can be heard across most of the school, to signal that a service or communion is starting. The funds for the Chapel were gifted by Mrs Margaret McWhae, who lived at 'Ellingerrin', a large pastoral property in the Western District of Victoria. Almost all of the materials used in the construction of the Chapel were sourced locally, with the sand and gravel coming from the nearby Delatite River, the stone from the school grounds used for the wing walls and the main altar, and the stone paving around the sanctuary taken from a nearby property bordering the Timbertop Creek that was owned by the Lovick family, another prominent family in the region. The only materials that were imported were the six beams which originated in Oregon. The Chapel's drawcard is a large triangular window, located behind the altar, which faces out toward the surrounding hills, with views extending across to Buttercup Ridge and the Glenroy Hills. As well as visiting guests and speakers, the chapel has seen weddings and funerals.

The 'Country Club' is the name given to a large flat section of ground located on the banks of the Timbertop Creek, where sports lessons typically take place. The Country Club has a basketball/netball court, and several fire pits.

The Darling Huts, between Scrubby Hill and Barclays Hill, are three huts: a timber slab dining hut, an accommodation hut and a mud-brick toilet block. The huts, which do not have electricity, allow students to stay overnight and learn about the flora and fauna on and around the campus. Students also get to cook pizzas and other meals.

Both the Dining Hall and the accompanying Amphitheatre are the central meeting points of the school. Students must assemble here at least three times a day, for breakfast, lunch and dinner, and must arrive on time. Failure to do so results in a small punishment run known as a "woodshed", where students must run from the Dining Hall, down the hill to a large woodshed, where almost all of the school's wood is stored, and then run up the hill. The dining hall's large verandah boasts picturesque views of the surrounding hills, and maintains an imposing location, being one of the first buildings of Timbertop seen on the drive into the school. At the end of meal times, a bell is rung by one of the teachers, and everyone must pause eating and drinking, and listen to news and information given by staff. Part of the Dining Hall includes the Mail Room, where incoming mail and newspapers are sorted and dispersed across the school. A select number of students from each unit, must take on the role of a dishwasher/cleaner, also known as a "slushie", at the end of each meal. Their job on "slush" duty is replaced weekly.

The John Lewis Centre, or JLC, is a semi-underground set of three classrooms that can combine into one room. This one room, encased with concrete, acts as a bunker to protect from bushfires, essentially acting as a 'last resort' should evacuation be impossible. The bunker was opened in 2011 as a response to previous bushfires that had managed to reach school grounds, including in 2006 and 2009.

Named after the previous family that owned the land that currently constitutes Timbertop, this track runs parallel with Grammar School Road, the main thoroughfare in and out of the school. This track is arguably more utilised than Grammar School Road, due its usage in several running and hiking routes. Additionally, the Klingsporn Track makes a feature in the route of the 'infamous' "Buller Road", a punishment run issued to select misbehaving students.

The geographically central part of the campus, this hill, at 652 metres, is completely covered in vegetation. The hill is cut in half by The Fire Break, which reaches across from the main gate toward Klingsporn Track. The hill is often included in runs in Term 1, as a particular section of the route that has a steep set of stairs is often deemed to be grueling by the new and unprepared students. Another prominent running route skirts around the western/northern side of the hill, where the track leads to Five Ways, an intersection where a track splinters off toward Darling Huts, and another leads on to Barclays Hill. A small clearing on the eastern side of the hill is known as the "Veggie Tip".

At the rear of the school lie two dams, the Swimming Dam (Bottom Dam), and the Drinking Water Dam (Top Dam). Almost all of the school's drinking supply originates from the Drinking Dam, where it is treated with UV, and transported around the school. The Swimming Dam is often used in the warmer months for sports lessons and a swimming test, but is also home to the "Head of the Dam", a parody of the Head of the River, a large rowing event held in Australia and other states in Australia, of which Geelong Grammar School takes part. Pool doughnuts are assembled and taped together in such a way to resemble a rowing boat, and students, using their arms as oars, must paddle from one side of the river to the other in a race.

Flowing directly through the middle of the campus, Timbertop Creek begins near the summit of Mount Timbertop, flows down Rhyolite Falls, before it passes through campus, where it reaches Monty's Weir, then onward through B Unit Flat, the Country Club, the base of Bald Hill and finally converges with the Delatite River off-campus near the township of Merrijig. The creek typically flows at its strongest in late winter/early spring as a result of snowmelt from further upstream.

Timbertop is home to a small vineyard, which was planted in the late 1980's. The vineyard, owned by Ross Ritchie Wines, produces red wines, including nebbiolo and merlot. Students who undertake agriculture, particularly viticulture, take part in the grape treading process, and other wine-making processes.

In 1966, King Charles III attended Timbertop for six months. The event was widely publicised. In 1973, the then Prince Charles said that his time at Timbertop was the most enjoyable part of his whole education.

In 1983, former UK Prime Minister, Boris Johnson, took a gap year as a teaching assistant at Timbertop.

In 1998, Missy Higgins attended Timbertop in M Unit, where she wrote the song "All For Believing". In 2001, the song would win Triple J's "Unearthed" competition. She wrote the lyrics of this song into the inside of the roof of her Unit.

In the late 1980s, writer John Marsden worked at Timbertop as head of English. While there, he made the decision to write for teenagers, following his dissatisfaction with his students' apathy towards reading, or the observation that teenagers simply weren't reading any more. Marsden then wrote So Much to Tell You in only three weeks, and the book was published in 1987. The book sold record numbers and won numerous awards including "Book of the Year" as awarded by the Children's Book Council of Australia (CBCA).

• Clark, Mary Ryllis; Geelong Grammar School (2003), Timbertop : celebrating 50 years, Geelong Grammar School, ISBN 978-0-947232-18-4
• Montgomery, Edward Hugh; Darling, J. R. (James Ralph), 1899-1995 (1967), Timbertop : an innovation in Australian education, Cheshire, retrieved 13 January 2018{{citation}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
• Ricketson, Matthew (17–18 April 1993). "Seeing the wood for the trees: Timbertop 40 years on. -The history of Geelong Grammar School-". Australian. Magazine: 26–27, 30–31, 33. Retrieved 13 January 2018.

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