Aruba is one of the four constituent countries that form the Kingdom of the Netherlands, together with the Netherlands, Curaçao, and Sint Maarten whose citizens share a single nationality: Dutch citizen. Unlike much of the Caribbean region, Aruba has a dry climate and an arid, cactus-strewn landscape. This climate has helped tourism as visitors to the island can reliably expect warm, sunny weather. About three quarters of the Aruban gross national product is earned through tourism or related activities. Most tourists are from Venezuela and the United States (predominantly from eastern and southern states).