The Sherif Halil Pasha Mosque, more commonly known as the Tombul Mosque, located in Shumen, is the largest mosque in Bulgaria and the second largest in the Balkans. Built between 1740 and 1744, it was initially located in the northeastern Bulgarian (then Ottoman) town's centre, but is now in Shumen's southwest parts as the town centre shifted. The mosque's name comes from the shape of its dome.
The mosque's complex consists of a main edfice (a prayer hall), a yard and a twelve-room extension (a boarding house of the madrasa). The main edifice is in its fundamental part a square, then becomes an octagon passing to a circle in the middle part, and is topped by a spheric dome that is 25 m above ground. The interior has mural paintings of vegetable life and geometric figures and features a lot of inscriptions in Arabic, phrases from the Quran. The yard is known for the arches in front of the twelve rooms that surround it and the minaret is 40 m high.