About 25km northwest of Santa Cruz, SANTIAGO – officially called San Salvador – is the fourth-largest island in the Galápagos at 585 square kilometres, and the last unpopulated one to have been abandoned by human settlers. In the early nineteenth century, Captain Porter is reputed to have set four goats free on the island, which swiftly set about multiplying, soon causing extensive damage to the island’s native wildlife. Before trained hunters, aided by dogs and satellite tracking systems, could get to work on the island’s 100,000 goats, its rampant feral pig population had to be eradicated, a mammoth task that took 28 years and was finally completed in 2001; the last goat was destroyed in 2005. As well as Santiago’s four visitor sites, there are some interesting satellite islands, such as Rábida, Bartolomé and Sombrero Chino, and its proximity to Santa Cruz means the majority of boat tours stop somewhere in this area. Day-trip boats based in Baltra also occasionally call at Bartolomé.