Lanzarote is a Spanish island, the northernmost and easternmost of the autonomous Canary Islands in the Atlantic Ocean. The capital is Arrecife. It is located approximately 125 kilometres (78 miles) off the north coast of Africa and 1,000 kilometres (621 miles) from the Iberian Peninsula. Lanzarote is the fourth-largest of the islands in the archipelago. In the centre-west of the island is Timanfaya National Park, one of its main attractions. The "Tunnel of Atlantis", the largest underwater volcanic tunnel in the world, is part of the Cueva de los Verdes lava tube.