The mosque Banya Bashi is situated in the centre of Sofia. It was built by the initiative and with the financial support of Mullah Efendi Kada Seyfullah and is also known as Mollah Efendi Mosque. According to local legends, it was designed by the famous Ottoman architect Mimar Sinan, who also built the mosque of Sultan Selim in Edirne and Suleymaniye Mosque in Istanbul.
     The main building has a square shape with four corners, one central dome, and a minaret. The mosque was built in accordance with the trends in architecture of the 16th century. It was made of stone and bricks. Nowadays this is the only operating mosque in Sofia.