St. Studios Monastery - Hagios Ionnes Prodromos Basilica - Ilyas Bey Mosquet
The building located in Yedikule is one of the oldest buildings of Byzantine in Istanbul. It was built in 5th century. Monastery and church was known as Studios due to its founder. Monastery was an important religious center during Byzantine period. During Latin invasion church-monastery was destroyed considerably, and in 13th century required repairs were made and building was surrounded by thick walls. The travellers arriving in Istanbul in 13th and 14th centuries mention fascinating decorations and splendid view of the church.
After Istanbul was conquered, the building was converted into mosque by Ilyas Bey in 1486. The building suffered considerable earthquake damages from earthquakes and fires occured in various periods and the roof of the building was demolished in 1908, and as it was not repaired the building has come to present time with its today's appearance. Specific columns, heads and some of architectural components of basilica and rich floor decorations have been preserved. Haghia Sophia Museum can be visited upon permission of directorate.