What is "kontoskalion"

The Kontoskalion , also known as Harbour of Julian , Portus Novus ("New Port"), or Harbour of Sophia , and in Ottoman times as Kadırga Limanı ("Harbour of the Galleys") was a harbour in the city of Constantinople, active from the 6th century until the early Ottoman period. In the literature it has been known under several names, and the sources about it are often contradictory.