Athens is the capital and largest city of Greece, with a recorded history spanning 3,400 years. It was a center for arts, learning, and philosophy in ancient times, home to Plato's Academy and Aristotle's Lyceum. The Olympic Games were first held in Olympia every four years from 776 BC, bringing together the city-states of Greece to compete in athletic and artistic events. Despite its democratic spirit, slavery remained common in ancient Athens, with slaves performing most productive tasks. Today, Athens is exceptionally rich in archaeological sites spanning from archaic Greece to the Roman era, many of which are open to the public.