Greece's capital is Athens. Its official language is Greek and its currency is the euro. Citizens of EU countries do not need a visa to visit Greece if their stay is less than 90 days, and they must have sufficient financial resources and return tickets. A valid passport is required for at least 6 months except for citizens of EU, Monaco, and Switzerland. Greece has a Mediterranean climate and a services-based economy. Popular cities include Athens, Thessaloniki, Heraklion, and Patras. Greek cuisine features Mediterranean influences and ingredients like olive oil, tomatoes, lamb, and dishes like gyros, dolmades, and fasolada.