The Temple of Olympian Zeus (Greek: Ναός του Ολυμπίου Διός, Naós tou Olympíou Diós), also known as the Olympieion or Columns of the Olympian Zeus, is a former colossal temple at the center of the Greece capital Athens. It was dedicated to "Olympian" Zeus, a name originating from his position as head of the Olympian gods. Construction began in the 6th century BC during the rule of the Athenian tyrants, who envisaged building the greatest temple in the ancient world, but it was not completed until the reign of the Roman Emperor Hadrian in the 2nd century AD, some 638 years after the project had begun. During the Roman period the temple -that included 104 colossal columns- was renowned as the largest temple in Greece and housed one of the largest cult statues in the ancient world.