Brimstone Hill is a fortification located on a 300-meter high hill on the west coast of St Kitts Island. The fortification was built by British engineers in the 18th century and served as the defense of the island, and this part of the Caribbean, under British control. At one time, this fortification was called Gibraltar Caribbean, because it was believed that the fortress was invincible. Brimstone Hill ended its military career in the second half of the 19th century, and the British Queen declared it a national park in 1985. UNESCO put Brimstone Hill on the World Heritage Site list in 1999, and the reason given is that this fortress is one of the best-preserved historical fortifications in the Americas.