The Athens municipality forms the core and center of Greater Athens, which consists of the Athens municipality and 34 more municipalities, divided in four regional units (Central, North, South and West Athens), accounting for 2,641,511 people (in 2011)[2] within an area of 361 km2 (139 sq mi).[17] Until 2010, these four regional units made up the abolished Athens Prefecture. The municipality of Piraeus, the historic Athenian port, with its 4 suburban municipalities make up the regional unit of Piraeus, which in turn forms Greater Piraeus.
http://www.cityofathens.gr/en/
