Given the name of the Holy Cross in Spanish, its English name derives from the British vessel HMS Indefatigable. It has an area of 986 square kilometres (381 sq mi) and a maximum altitude of 864 metres (2834 ft). Santa Cruz is the island that hosts the largest human population in the archipelago at the town of Puerto Ayora. The Charles Darwin Research Station and the headquarters of the Galápagos National Park Service are located here. The GNPS and CDRS operate a tortoise breeding center here, where young tortoises are hatched, reared, and prepared to be reintroduced to their natural habitat. The Highlands of Santa Cruz offer an exuberant vegetation and are famous for the lava tunnels. Large tortoise populations are found here. Black Turtle Cove is a site surrounded by mangrove which sea turtles, rays and small sharks sometimes use as a mating area. Cerro Dragón, known for its flamingo lagoon, is also located here, and along the trail one may see land iguanas foraging.