Genovesa Island (Spanish: Isla Genovesa), referred to in English as Tower Island, is a shield volcano in the Galápagos Islands in the eastern Pacific Ocean. The island occupies about 14 square kilometres (5 sq mi), and its maximum elevation is 64 m (210 ft).[citation needed] The horse-shoe shaped island has a volcanic caldera whose wall has collapsed, forming the Great Darwin Bay, surrounded by cliffs. Lake Arcturus, filled with salt water, lies in the centre, and sediment within this crater lake is less than 6,000 years old. Although no historical eruptions are known from Genovesa, there are very young lava flows on the flanks of the volcano.
The official Spanish name “Genovesa” is from the Italian city of Genoa, in honor of Christopher Columbus. The English name “Tower” is presumably a corruption of “Downes”. The island’s position was reported by John Downes of the USS Essex in 1813, during the War of 1812, and the name “Dowers’s” appeared in 1815, presumably a misspelled reference to Downes. After passing through “Dowers’s”, “Dowers”, and “Tower’s”, by 1841 it was written as “Tower” in the British Admiralty chart.
