Walled Obelisk

The Walled Obelisk (also known as Constantine Obelisk) is situated near Serpentine Column, Egyptian Obeliskand German Fountain is also its neighbour,which is located in front of Serpentine Column, at the southern side of the Hippodrome of Constantinople (now Sultanahmet Square). The 32 meter-high obelisk was constructed of roughly cut stones by Constantine VII. Its exact construction date is unknown, but it is named after Constantine VII after he repaired it in 10th century. At that time, it was reportedly decorated with gilded bronze plaques that portrayed victories of Basil I who was grandfather of Constantine VII. Also there was a sphere at the top of obelisk. However, reportedly these gilded bronze plaques were stolen and melted by Fourth Crusaders in 1204.

Since young Janissaries liked to use the obelisk to climb and show their prowess, the obelisk stone surface suffered further damage to its surface.

Source: http://en.wikipedia.org