Key West is an island and city in the Straits of Florida on the North American continent. The city lies at the southernmost end of US 1, the longest north-south road in the United States,. Key West is the southernmost city in the contiguous United States. The island is about 4 miles (6.4 km) long and 1 mile (1.6 km) wide, with a total land mass of 4.2 square miles (11 km2) and lies at the end of the Florida Keys island chain. Duval Street, its main street, is 1.1 miles (1.8 km) in length in its 14-block-long crossing from the Gulf of Mexico to the Straits of Florida and the Atlantic Ocean. Key West is about 95 miles (153 km) north of Cuba at their closest points.