The largest and oldest surviving mosque of Serres and one of the largest in the Balkans is located at the eastern end of the city. Built-in 1492-1493 by Mehmet Bey, son-in-law of Bayezid II, it is part of the largest building complex that remains and is known to the locals as "Agia Sophia".
It consists of a spacious square central space, covered by a huge dome that reaches a height of 26 meters. Four side rooms covered with lower domes surround the central area from east and west. On the south wall, the five-sided "mihrab" arch protrudes in the plan.
The columns and capitals, decorated with prismatic stalactites of exceptional style, are made of white marble, while the inscription with the name of the founder and the year of construction is preserved. The building was extensively damaged by floods in the 19th century so today the mosque that the visitor can admire is preserved.