Achaea (/əˈkiːə/) or Achaia (/əˈkaɪə/), sometimes transliterated from Greek as Akhaia^[1] (Αχαΐα, Akhaïa [axaˈia]), is one of the regional units of Greece. It is part of the region of Western Greece and is situated in the northwestern part of the Peloponnese peninsula. The capital is Patras which is the third largest city in Greece. Its population surpassed 300,000 for the first time in 2001.