The Galapagos Islands are an archipelago of 19 islands straddling the equator in the Pacific Ocean, 525 miles west of the coast of Ecuador. Sitting atop the Galapagos hotspot, a place where the earth's crust is being melted from below, the islands were formed by underwater volcanoes. They are geologically young and are famous for the large number of species of plants and animals found only there. The ocean temperatures and climate are controlled by the Humbolt stream and the El Nino that brings a variety of weather conditions. Post Office Bay on Floreana Island is the site of the original Post Office barrel. It was put in place in 1793 by British whalers to send letters home. The barrel remains a well known location for letters to be picked up or sent. Taugus Cove was a well known Galapagos location for whalers to anchor. Above the cove is Darwin Volcano and a saltwater lake above sea level. It is thought that the salt water moves up to the lake through the porous volcanic rock. A monument to sailors who were lost at sea rests along the side of the trail to the lake.