The Hippodrome of Constantinople was a large horse racing arena and center of social life located next to the imperial palace in Constantinople. It was constructed in the early 4th century under Emperor Constantine and could hold over 100,000 spectators. Horse and chariot races were popular events along with riots between factions that supported the Blues, Whites, Greens or Reds teams. Today, remains of the hippodrome can be seen in Istanbul's Sultan Ahmet Square.