Isa Bey Mosque is situated in the Selçuk district of İzmir Province in Turkey, close to the ancient city of Ephesus. Built in 1375 by the architect 'Ali son of Mushimish al-Dimishki,' under the orders of the Aydinid İsa Bey, this mosque is a historical monument that stands testament to Anatolian beylik architecture. It combines both Seljuk and Ottoman architectural styles, making it unique. The mosque features a courtyard, a large prayer hall, and an impressive portico adorned with columns taken from Roman ruins, reflecting the classical influences of the region. It was built using local stones and marbles from the ruins of Ephesus, and the interior has a mihrab and minbar beautifully crafted, reflecting the intricate work of the artisans. Isa Bey Mosque is celebrated for its intricate carvings, geometrical designs, and artistic calligraphy which adorn its doors and window frames. It also boasts an exceptional asymmetrical layout which was avant-garde for its time. Historically, it was part of a complex that included a madrasa and a hammam, and until the 19th century, it was used as a caravanserai.