The Serpent Column (Yilanli Sutun) is a historical monument that stands in the Sultanahmet Square in Istanbul, Turkey. It is a bronze column that has three snake heads at the top, but only one of them is partially preserved. The other two heads are missing, and one of them is displayed in the Istanbul Archaeology Museum.

The Serpent Column (Yilanli Sutun) was originally made in ancient Greece, around 478 BC, to celebrate the victory of the Greek city-states over the Persian Empire at the Battle of Plataea. The Serpent Column (Yilanli Sutun) was part of a sacrificial tripod that was dedicated to Apollo, the god of light and prophecy, at his sanctuary in Delphi. The names of the 31 Greek city-states that participated in the battle were engraved on the coils of the snakes.

The Serpent Column (Yilanli Sutun) was moved from Delphi to Constantinople (the former name of Istanbul) by Emperor Constantine I in 324 AD, when he founded his new capital city. He placed the Serpent Column (Yilanli Sutun) in the Hippodrome, a large arena for chariot races and other public events. The column was a symbol of the continuity and legitimacy of his rule, as well as a reminder of the ancient Greek culture and civilization.

The Serpent Column (Yilanli Sutun) has survived many wars, earthquakes, and fires throughout its long history. It has also witnessed many important events and changes in the city. It is one of the oldest and most remarkable monuments in Istanbul, and a popular attraction for tourists and locals alike.

The golden tripod of monument was lost long before it was brought to Istanbul in Constantine the Great era. Snake heads survived till the beginning of 18th century and they were broken in this period. One of the serpent heads survives in the Museum of Antiquities, in Byzantine Hall.