Pictures on the web speak of the “Orphanage of Hagios Paulos “. Turkish name "Hagios Paulos Yetimhanesi"

A notice on site first speaks of the "Orphanage of Hagios Paulos", also known as the Byzantium Orphanage. That was built by Emperor Justinian I and his wife Sophia in 579. A spring at (or near?) it is called the Therapon Holy Water Spring and the same notice claims that is what the word “therapy” is derived from.
Also it states that between 1042 and 1054 a “Hagios Monastery and church” were built and were (later, earlier?) used as storage for battle equipment and served as a monastery. If that was part of the remains is not clear.