San Cristóbal is the most easterly island and the only island with a permanent freshwater lake, Laguna El Junco. The sleepy port town of Puerto Baquerizo Moreno is the capital of the Galapagos province while the island's population is the second largest in the archipelago. Geologically, San Cristóbal is also one of the oldest of the islands in the group.
Less flattering to the island's reputation is the impact that human activity has had on San Cristóbal’s fragile environment over the centuries since it was first colonised. Introduced plants such as guava and blackberry have encroached on the once extensive scalesia forest, and the miconia zone is a fragment of its former glory. Domesticated animals such as goats, pigs, dogs and cats have also had a dramatic impact, leading to the significant decline and even extinction in a number of native species. A number of conservation and habitat rehabilitation programs are underway, and the Galapagos National Park Service Interpretation Centre at Puerto Baquerizo Moreno is a good source of information about these.
The island rises to a height of around 900m above sea level, and it is in the misty damp of the highlands remaining miconia stands that the lake, El Junco, is to be found. Sitting in an almost perfectly round crater within a hard to distinguish volcanic caldera, the lagoon's area of 60,000 square metres is popular with many bird species including frigatebirds that turn up to have a quick rinse in the freshwater to wash the salt from their feathers. The surrounding highlands are also home to around 1,000 Chatham giant tortoises, with the best opportunities of seeing them being found at Galapaguera in the southeastern part of the island.
At the north of the island, good opportunities for snorkelling are to be found at Cerro Brujo, a picturesque fine white sand beach that is quite possibly one of the best in the Galapagos. At Punta Pitt, a spectacular eroded volcanic cone further round the northeastern tip of the island, is the one and only opportunity to see all three of the Galapagos boobies species nesting side-by-side. This island is a great destination by either Galapagos cruise or by land tour.