The Virgin Islands consists of the main islands of St. Thomas, St. Croix, and St. John. The islands are 133.73 square miles and are between the Caribbean Sea and the North Atlantic Ocean, east of Puerto Rico. As of July, 2008 the population was estimated to be at 109,840. The main industry in the Virgin Islands is tourism. The Virgin Islands are the most popular vacation destination in the Caribbean. St. Croix is also the home of one of the world's largest petroleum refineries. Tourists will find that the island's clean beaches, clear water and ethnically diverse culture are enchanting.