The Gornjak Monastery (Serbian: Манастир Горњак, romanized: Manastir Gornjak), also known as Ždrelo (Ждрело), is a 14th-century Serbian Orthodox monastery located in the vicinity of today's city of Petrovac, Serbia.

Gornjak monastery is located in Gornjacka gorge, between Žagubica and Petrovac na Mlavi. Construction of the monastery was finished in 1380 by Starats (Elder) Grigorije and his brethren, and the founder was King Lazar of Serbia.

Ždrelo Monastery, later called Gornjak, on a small plateau above the left bank of the Mlava under the steep cliffs of Ježevac Mountain, is the endowment of Prince Lazar. The surrounding area is so beautiful and colorful that Đura Jakšić sang in delight: "From Veliki Selo to Ždrel itself, it's as if a fairy has spread a carpet." Felix Kanic wrote: "We stopped as if mesmerized by the luxurious idyll of this region where Serbian hermits lived."

The monastery was built in 1378, when the prince issued the founding charter, and Patriarch Spiridon confirmed it with his spiritual authority. As the motive for building the monastery, Prince Lazar cites the desire to make a small offering to the Mother of God "with the hope of her help at the Last Judgment of Christ". But, apart from spiritual reasons, there are also certain political reasons for building this monastery. Namely, Lazar had just mastered these regions, so he wanted to mark it with his endowment. The following winter or spring, Radič, son of Branko Rastislavić, overthrew the power of Lazarev, and as the monastery and the founding composition in the church, depicting Lazarus and his family, still reminded him of this, he damaged the monastery. By May 1379, Lazar beat Radič again and took away his property, and gave the monastery to the newly arrived Grigori Sinait - the Younger, who worked with the brotherhood "for the elevation and construction of the temple of that and other sages" but with the financial "help of Mr. Prince Lazar ". In the same year, Lazar issued another charter, which was also confirmed by the Serbian patriarch. If it is not a later interpolation (forgery), the monastery is exempted from the authority of the competent bishop, except for spiritual affairs and the right of mention, and the monks are left with the right to choose their own abbot. To support the monastery and brotherhood, Lazar donated many villages in Braničevo, Stig, Homolj and Podunavlje to Gornjak. The original charters were not preserved, but came down to us in a later and rather bad copy, where the first charter of the prince and both of the patriarchs were drawn up at the same time, while the second charter of the prince was lost. Such a charter was published by: Franz Miklošič (after Joakim Vujić's copy) and Šafarik (after Vuk Karadžić's copy).

• Monument of Culture of Exceptional Importance
• Tourism in Serbia

44°15′57″N 21°32′37″E / 44.2658°N 21.5436°E / 44.2658; 21.5436