The mosque Banya Bashi is situated in the centre of Sofia. It was built by the initiative and with the financial support of Mullah Effendi Kada Seyfullah and is also known as Mullah Effendi Mosque. 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 and four corners and one central dome, and a minaret. The mosque was built in accordance with the trends in architecture in the 16th century. It was made of stone and bricks.