The islands of the Caribbean Sea, collectively known as the West Indies are sorted by size and location into the Bahamas (or Lucayan archipelago), the Lesser Antilles and the Greater Antilles. The Greater Antilles are Cuba, Jamaica, Hispaniola (composed of Haiti on the west side and the Dominican Republic on the east side) and Puerto Rico. The smaller islands in the vicinity of these four major islands are sometimes also treated as part of the group. This includes the smaller islands thst surrounding the main islands, but are still part of the main island country (e.g. the Republic of Cuba consists of the island of Cuba and several smaller islands around it). The Cayman Islands are also often included in the Greater Antilles because of their geographical proximity. The Greater Antilles are made up of continental rock, distinct from the Lesser Antilles, which are mostly young volcanic or coral islands.