Useful information for E.U. citizens travelling to Greece:
Travel documents: A passport is not required for E.U. citizens travelling from or to Schengen countries.
Currency (EURO): No limit
Customs Formalities: None
Forbidden substances: Drugs, explosives etc. Travelers in possession of codeine-based medication are subject to severe penalties, unless they declare their possession
Health: Vaccines are not required for E.U. citizens