San Cristóbal (Chatham) is the easternmost island in the Galápagos archipelago, as well as one of the oldest geologically. It is administratively part of San Cristóbal Canton, Ecuador.
Its Spanish (and official Ecuadorian) name "San Cristóbal" comes from the patron saint of seafarers, St. Christopher.
English speakers increasingly use that name in preference to the traditional English name of Chatham Island, derived from William Pitt, 1st Earl of Chatham.
San Cristobal Island is composed of 3 or 4 fused volcanoes, all extinct. It is home to the oldest permanent settlement of the islands and is the island where Darwin first went ashore in 1835.
A small lake called El Junco is the only source of fresh water in the islands. The availability of fresh water is what led to the early settlement of San Cristobal.
A penal colony was built on San Cristóbal Island in 1880 for prisoners from mainland Ecuador.
This later turned into a military base for Ecuador and export center for the island's products including sugar, coffee, cassava, cattle, fish and lime.
It has an area of 558 km2 (215 sq mi) and its highest point rises to 730 metres (2,400 ft). The population is approximately 6000.
It is the most fertile island of the archipelago and is the second most populated after Santa Cruz.
The capital of the archipelago, Puerto Baquerizo Moreno, lies at the south-western tip of the island.
This island hosts frigatebirds, Galápagos sea lions, Galápagos tortoises, blue and red footed boobies, tropicbirds, marine iguanas, dolphins and swallow-tailed gulls. Its vegetation includes Calandrinia galapagosa, Lecocarpus darwinii, trees such as Lignum vitae, Matazarna. In the waters nearby are sharks, rays, and lobsters.
Reference: Wikipedia