Genovesa Island, named after the Italian city of Genoa, in honor of Christopher Columbus, (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). 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.