This mosque is located in the Old Town (Kastel) , not far from the main (western) gate and city ramparts. It was built of hewn stone and covered with a four-pitched roof in imitation of a dome under eternite. A stone minaret of octagonal shape, 16 m high, was built along the right wall and was one of the most beautiful in Herzegovina. It was built in 1726 and is the endowment of Osman Pasha Resulbegović. The builders were masters from Dubrovnik. There are elements of Mediterranean architecture in its construction. It is famous as the most spacious mosque in Herzegovina. Before the war, it was a cultural monument under state protection. Osman Pasha built a mekdeb and a madrasah near the mosque, which were the first educational institutions in Trebinje. After the construction of the mosque, Osman Pasha was accused in Istanbul of having built a more beautiful mosque than the emperor’s in his own name in Trebinje . Because of this, Sultan Ahmed III issued an order condemning him and his nine sons to death. Osman Pasha Resulbegović went to Istanbul to beg for pardon, but his was refused, and he was executed in 1729.