Sultanahmet Square is built on top of the Hippodrome, the chariot-racing arena that was the political centre of Byzantine Constantinople. The oval shape of the modern square still follows the track.
Three monuments survive along the central line. The Obelisk of Theodosius is Egyptian, carved for Thutmose III around 1450 BC and brought here in 390. The Serpent Column came from Delphi and was cast from the weapons of defeated Persians. The Walled Obelisk is the youngest, and lost its bronze plating to crusaders in 1204.
The square is open at all hours and free. Early morning is the only time it is quiet.
From The Soul Hotel take the T1 tram from Karaköy to the Sultanahmet stop, which puts you at the northern end of the square.