The Sherif Halil Pasha Mosque, more commonly known as the Tombul Mosque, located in Shumen, is the largest mosque in Bulgaria and one of the largest in the Balkans.
Build between 1740 and 1744, the mosque was initially located in the north-eastern Bulgarian (then Ottoman) town's centre, but is now in Shumen's south-west parts as the town centre moved as a result of the enlargement of the town. The mosque's name comes from the shape of its dome.
The mosque's complex consists of a main edifice (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 spherical dome that is 25 m above ground. The interior has mural paintings of vegetable life and geometric figures and inscriptions of Arabic, phrases from the Qur'an. The yard is known for the arches in front of the twelve rooms that surround it and the minaret is 40 m high.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.