A ‧ crop ‧ o ‧ lis, the /əˈkrɒpəlɪs $ əˈkrɑː-/ BrE AmE
the ancient ↑ citadel (=a place people can go to if their city is attacked) of Athens, built on a hill in the centre of the city. There are many important ancient Greek buildings on the Acropolis, such as the Parthenon, and it is visited by many tourists.