Even if you arrived in Athens without knowing what akropolis is(which would be hard to believe), you'd wonder what's that white building you see on the hill almost from everywhere in the town centre. Acropolis means upper city and there are many all around Greece but the one in Athens is definitly the most popular. You can easily arrive at Acropolis using the underground or having a nice walk from Plaka. It's open from 8 to19 (from april to october) and from 8 to 17(from november to march). The 12€ ticket allows you also to visit: ancent Agorà, Roman agorà, hadrian library, Zeus temple and Dyoniso's theater, theater where dramas of Sofocle, Eschilo and Euripide were played.