A mosque that began to be built at the end of the 14th c. by Sultan Bayezid I Gildirim to whom it owes its name. It is on the central square of Didymoteicho, on the road that led to the main gate of the castle, and is one of the most majestic Ottoman mosques in Greece. An inscription above the entrance states that its construction was ordered by Muhammad I in 1420. Another inscription on the side entrance states the year 1421.
The building is almost square with three doors. The main entrance has arabesque and archaic motifs. Inside the mosque, the dome and the representation of the heavenly city above the sanctuary are impressive. The walls are decorated with passages from the Koran. The mosque has a minaret with its own external entrance and a balcony. A second one was added later on.