Save for the crumbled stones of a handful of dungeons and towers, this is all that remains of the palace complex of Blachernae, and one of the few secular Byzantine buildings that remain, comparatively, intact. It is hard to imagine the opulence of the palace at its zenith; however, one could hazard a guess if it's true that the Stonemaker's Diamond -- the one in the Topkapi Treasury -- was found in the rubble here. The building is usually identified as the Palace of Constantine Porphyrogenitus and dated to the 13th century. Typical of Byzantine construction, the palace walls are made of alternating brick and marble.