Triyuga (Nepali: त्रियुगा) is one of the eight municipalities of Udayapur district of the Koshi Pradesh of Nepal. Gaighat is the headquarter of the municipality. According to the 2021 Nepal census the total population of the municipality is 103,475. It is divided into 16 wards. Triyuga Municipality was established on B.S. Chaitra 13, 2053 (26 March 1997). It was named after Triyuga River. A river which flows through the town. Triyuga is the 3rd largest municipality in Nepal and 1st largest in Koshi Pradesh in term of size (area). The total area of the municipality is 547.43 square kilometres (211.36 sq mi)

Almost all facilities are available in the town. Schools, colleges, Hospitals and clinics are available in the town. There are six police stations and armed police force in the town, and an army barrack is also situated in the city.

Triyuga municipality was established on 26 March 1997 merging 3 VDCs: e.g. Gaighat, Deuri and Bhumarashuwa. Total area of the municipality was 319.88 square kilometres (123.51 sq mi).

On 6 March 2017, following VDCs added into Triyuga municipality: Jogidaha, Saune, Khanbu and Jalpachilaune. Now total area of the municipality is 547.43 square kilometres (211.36 sq mi).

Triyuga municipality is divided into 16 wards:

Ward No.	Admin. Centre	Area (km)	Pop. 2011	Pop. 2021
1	Jogidaha	46.5	5115	4658
2	Motiyahi	47.15	6403	5830
3	Motigada	30.05	8630	9997
4	Salghari	48.38	5962	5666
5	Deuri	44.79	7745	6983
6	Jaljale	38.03	8217	8820
7	Chuhade	40.31	8145	6733
8	Rajabas	19.4	6565	5468
9	Gairun	19.4	5813	5575
10	Bokse	3.81	8394	8265
11	Gaighat	12.3	7932	11400
12	Old Gaighat	3.81	6311	7907
13	Dhik	33.49	6832	6386
14	Saune	76.97	3008	2312
15	Ranibas	44.13	4893	3541
16	Chilaune	38.9	4552	3184

Triyuga is one municipality out of four municipalities of Udayapur District. The municipality is surrounded by Mahabharat hills in north and Churey hills in south. Udayapurgadhi and Rautamai are in north of the municipality, Khotang District is in north-east and Chaudandigadhi Municipality is in east. Saptari District is in south of Triyuga Municipality.

This city is in the famous Udayapur Valley. Gaighat (गाइघाट) (other name of Triyuga) is the shadow of a historic kingdom of Sen dynasty in Udayapurgadhi (Chaudandi), this Inner Terai Valley of south-eastern Nepal has a glorious history with a bright future. Gaighat is in the plane of the Valley. Udayapur Valley is the largest valley in eastern Nepal having fabulous natural attractions such as the Triyuga river, Baruwa river flowing through the town. Koshi River is east of the city.

The total population of the municipality, as of 2011 Nepal census is 87,557 in which male comprises 41,221 and female 46,336. There are 19,484 households. 74% of people of the municipality is educated. 82% male and 66.5% female are educated.

Chetri is the largest group of caste in Triyuga municipality which comprises 24.24% of people of total population of Triyuga. The second largest group of caste is Tharu people which comprises 14.91%. Rai 12.43%, Magar 9.04%, Bahun (Hill Brahman) 7.74% comprises total population of the municipality.

Nepali language is the mostly spoken language in Triyuga, which is spoken by 55.82% of people. Tharu language is secondly most spoken language, Maithili language is third most spoken language and Magar is fourth.

The total population of Triyuga municipality in 2021 has been increased compared to 2011 Nepal census. According to the 2021 Nepal census, there are 102,725 people living here in 25623 households. The number of males comprises 48463 (47.2%) while females are 54262 (52.8%). Sex ratio is 89.31/100 female. 188 people live per square km.

Ethnically Chettri is the largest group in this rural municipality following Tharu second largest, Rai at third, Magar at fourth and Bahun at fifth position.

Religiously Hindu is the largest group with 77.3% and Kirat Mundhum is the second largest group with 9.1%, Buddhist at third number with 8%.

Religious group percentage Hindu   77.3% Kirat Mundhum   9.1% Buddhist   8% Christian   2.1% Islam   1.7% Others   1.8%

80% of the total population are literate which means they can read and write but only 13.2% of people have passed SEE.

Education percentage Basic   4.7% primary   27.7% secondary   34% SEE   13.2% 10+2   12.6% Graduate & above   5.1%

Nepali is the most spoken language in this municipality with 55.3%, Tharu is second with 14.6%, Maithili is third with 7% and Magar is at fourth with 6.5%. Chamling, Tamang, Rai, Danuwar and Nepal bhasha are other minor languages that are also spoken in this municipality.

Languages percentage Nepali   55.3% Tharu   14.6% Maithili   7% Magar   6.5%

Education in the town is accessible. Campuses for higher education are available at Gaighat. Triyuga Janata Multiple Campus provides undergraduate and post graduate education on management and social sciences. Baruwa Campus provides undergraduate education, management and science. Similarly Udayasi English higher secondary school provides intermediate education on science and management. There are numerous other schools for education, such as:

• 1. Himalayan Dale Academy, Bokse
• 2. Paradise Secondary school, Gaighat
• 3. Udayapur English School, Gaighat
• 4. Laligurans Secondary school, Gaighat
• 5. Canvas Secondary school, Gaighat
• 6. Sagarmatha Secondary school, Purano Gaighat
• 7. Rastriya janata higher secondary school, Bagaha
• 8. Janajyoti higher secondary school, Chuhade
• 9. Shree janata Higher Secondary School Deory
• 10. Evergreen Secondary English Boarding School
• 11. Shree Ram Janaki higher Secondary School, Motigada
• 11. B.D.M. English Boarding School, Motigada
• 13. Udayasi English Higher Secondary school, Jaljale
• 14. Baruwa Campus, Gaighat
• 15. Peace-Zone international Academy, Gaighat
• 15.Triyuga Janata Multiple Campus, Motigada
• 16.Shree Balmandir Secondary School, Bokse

Tharuhat Rangsala

Football, cricket and Cycling are the most popular sports in Gaighat. Tharuhat Rangsala with a capacity of 10,000+ spectators is the largest football stadium in the city. The Udayapur Gold Cup, is held in the stadium with National Football Clubs as well as District Clubs. There is a covered hall at Bokse, where indoor events can be organized. Other facilities in the city includes Boxing Ring, Karate Ring, Table tenniscourt, Lawn Tennis court and Badminton court.

Road & Highway route
Khanbu, Khotang KTM, Sindhuli Chatara, Dharan KTM, Lahan Itahari, Mechinagar Bhagwanpur Thadi Laukaha

The Sagarmatha Highway (NH-16) via Thadi Border, (Saptari) connects Gaighat to Bihar (India). Mahendra Highway (NH-01) crosses NH-16 at Kadmah-Lahan (Saptari) which connects Gaighat with all other parts of the country. NH-16 also connects Gaighat to Khotang and Solukhumbu Districts. Likewise Madan Bhandari Highway (NH-09) goes through the city which connects Dharan in the East and Sindhuli in the west. The highway is opened after the completion of chatara bridge over Koshi.

Public buses are available from Kathmandu, Biratnagar, Kakarbhitta and other cities to move to the city. Local transportation is available within the town. Many small local routes have public transport facilities. Tempos and taxis are available for rent too. Sagarmatha airport is proposed to be constructed in the city.

• Rajbiraj Airport (57 km by road)
• Janakpur Airport (116 km by road)
• Biratnagar Airport (138 km by road)

Rajbiraj Airport is the nearest airport, roughly 57 km away. Shree Airlines and Buddha Air operates daily flights between Rajbiraj and Kathmandu

The town in connected to Indian border via Thadi in Nepal and Laukaha in India which is 51 km South of Gaighat are a part of one of the agreed route for Mutual Trade between India and Nepal. Nepal Government of Nepal has set up a dedicated customs office in the town. and Government of India has set up a Land Customs Station with a Superintendent level officer. Laukaha has Laukaha Bazar railway station which is a big line and connects to rest of India via Train and NH57 via road.

Communication facilities is available in the town. Internet services are provided by Nepal Telecom, Subisu, Broadlink, Worldlink. Telephone services are provided by Nepal Telecom, Ncell and United Telecommunications. Both Pstn as well as cellular phones can be used in the city.

Following banking and financial institutions provides services in the city.

• Nepal Investment Mega Bank
• NIC Asia Bank Limited
• Global IME Bank Limited
• Rastriya Banijya Bank
• Nepal Bank Limited
• Citizens Bank International Limited
• Laxmi Sunrise Bank Limited
• Agriculture Development Bank
• Himalayan Bank Limited
• Kumari Bank Limited
• Sanima Bank
• Everest Bank Limited
• Nabil Bank Limited
• Siddhartha Bank Limited
• Machhapuchchhre Bank
• Prabhu Bank Limited
• NMB Bank Limited
• Shangrila Development Bank
• Kamana Sewa Bikash Bank
• Jyoti Bikash Bank
• Muktinath Bikash Bank

Hotels and restaurants are available in Gaighat. Resorts are available near Koshi Tappu Wildlife Reserve and in town. Lodges and resorts with sufficient services are available. Hotels and lodges delivers proper hospitality to the guest in the town. Fooding and lodging are available in the hotels of the town. Some of the hotels are Gangachuli Hotel, Hotel A-one, Sital Chautari.

National daily newspapers like Kantipur, The Kathmandu Post, Annapurna post, The Himalayan Times, Nagarik, Republica, Gorkhapatra are available in early morning. Local television named G-music is broadcast via cable. To promote local cultures Triyuga has FM radio stations Radio Triyuga 104 MHz, Radio Udayapur 102 MHz and which are Community radio Stations. Radio Amurta 91.6 is a commercial fm station in Tyiyuga. Cable television service is also available. Many local newspapers are published in the town on daily, weekly basis. Some of them are Majhkharka, Triyuga post, Baruwa Times.

• 
  A view of a street to main chowk, Gaighat Bazar from Pipal Chowk
• 
  Triyuga higher secondary school
• 
  Radha-Krishna Temple

• Katari
• Belaka
• Chaudandigadhi

• UN map of the municipalities of Udayapur District
• Udayupur Valley / Gaighat information
• Koshi Camp
• Udayapur.com Archived 2007-06-12 at the Wayback Machine