Sombrero, also known as Hat Island, is part of the British overseas territory of Anguilla and is the northernmost island of the Lesser Antilles. It lies 54 km (34 mi) north-west of Anguilla across the Dog and Prickly Pear Passage. The distance to Dog Island, the next nearest island of Anguilla, is 38 km (24 mi). Sombrero is 1.67 kilometres (1,830 yd) long north-south, and 0.38 km (420 yd) wide. The land area is 0.38 km² (94 acres). Originally, when viewed from the sea, the island had the shape of a sombrero hat but guano mining operations have left the island with precipitous sides and a relatively flat top which is 12 m (39 ft) above sea level.