Ancient theater of Epidaurus, Greece © George Pachantouris/Getty Images
Hidden in the eastern hills of Greece’s Peloponnese peninsula, about 100 miles from Athens, lies the ancient theater of Epidaurus. Built in the 4th century BCE, this massive open-air venue, which could hold about 14,000 spectators, is known for its perfect architectural proportions. It sits alongside several ancient Greek monuments in the wider Sanctuary of Asclepius, a UNESCO World Heritage Site.