If you reside in another country, you will have to go through customs control on arrival, where you may be asked, in addition to a passport and other supporting documents, for a visa, travel documents such as return tickets or tourist itinerary, accommodation reservations and proof of sufficient financial means during your stay in the form of cash, cheques, letters of payment or credit cards (minimum amount of 100 euros per person per day, with a minimum of 900 euros or equivalent in foreign currency).
Find out if the country you are coming from requires a visa by clicking here.