The port of Piraeus is the chief port in Greece, the largest passenger port in Europe, and the third largest in the world, servicing about 20 million passengers annually. Although not really attractive to tourists, the confusing, bustling port of Athens is the departure point for hundreds of island ferries and cruise ships, so most tourists will pass through it while visiting Greece. Piraeus has been Athens' port since ancient times and was for many years the chief harbour of Ancient Greece. Piraeus was a city, not merely a port, and was once separated from the mainland, occupying its own rocky island. Today it is part of Athens and the port actually consists of three harbours, with most of the tourist boats using the Zea Limani section. There are several good fish restaurants in the harbour precincts, and a sprawling street market. Visitors with time on their hands while waiting for ferries can also explore the Maritime Museum at Akti Themistokleous, alongside the pier used by the island hydrofoils, which features models of ancient and modern ships. There are also archaeological sites at the port, including the remains of some of the ancient fortifications of the harbours.