When HMS Beagle reached the Galapagos in September 1835, Charles Darwin went ashore here. San Cristobal was the first island he stepped onto, and the bay near what is now Las Tijeretas - Frigatebird Hill - is where the boats made landfall. The archipelago he would eventually describe in On the Origin of Species began, for him, on this particular strip of volcanic coast. The island itself is one of the oldest geologically in the Galapagos, composed of three or four fused volcanoes, all now extinct. Its 730-meter high point, population of about 6,000, and area of 558 square kilometers make it modest in size, but it sustains what few Galapagos islands can: year-round human settlement, drawn here originally by the one resource this archipelago almost uniformly lacks.

Up in the highlands, in the southern half of the island, El Junco lake fills a volcanic crater at about 700 meters elevation. It is the only large body of fresh water in the entire Galapagos archipelago. The availability of that water is why San Cristobal became the first permanent settlement of the islands - sailors could refill their casks here in a way they couldn't anywhere else. Reaching the crater today means climbing a set of steep steps from the parking area, but the view that opens at the rim stretches 360 degrees across the island. A narrow circuit trail follows the crater edge, muddy in places, threading through the vegetation that crowds the lake. The water below draws birdlife in concentrations that would be routine in most places and feel almost shocking here.

Offshore, a vertical slab of rock rises from the water - Leon Dormido in Spanish, 'sleeping lion,' for its resemblance to a reclining cat. The English name, Kicker Rock, is older and stranger. British captain James Colnett charted this coast in 1793 and named the formation, probably in reference to two navigational towers in Hampshire - Kickergill and Gilkicker - that guided ships into Portsmouth Harbour in the seventeenth century. Colnett gave the island itself the name Lord Chatham Island that same year, for John Pitt, 2nd Earl of Chatham and First Lord of the Admiralty. The Spanish name San Cristobal - Saint Christopher, patron saint of sailors - eventually prevailed. Today the rock is a dive site where snorkelers drift past sea turtles, white-tip reef sharks, and occasional hammerheads. The water is deep and the current can run strong.

La Galapaguera de Cerro Colorado, along the road between El Junco and Puerto Chino, is a reserve set aside for the repopulation of San Cristobal's variety of giant tortoise. The tortoises were moved here from the northern part of the island to protect the breeding program. Pens hold animals up to age five, after which they are released. Trails wind through the reserve, and admission is free. Closer to Puerto Baquerizo Moreno, the Interpretation Center - ten minutes walk from the town center - tells the longer story: how the Galapagos formed, how they were settled, how conservation happens. A penal colony was built on San Cristobal in 1880 for prisoners from mainland Ecuador, which later became a military base and an export center for sugar, coffee, cassava, cattle, fish, and lime.

Getting to Punta Pitt requires a boat and a guide. The northeast tip of the island is a wet landing site - you step off the inflatable into shallow water and wade to the beach - and it is one of the few places in the archipelago where all three booby species nest in the same area. Blue-footed boobies with their absurd cerulean feet, red-footed boobies that perch in trees, and masked boobies with their black-and-white plumage. Lava formations from older eruptions cast the landscape in dark, eroded shapes. Frigatebirds sometimes patrol overhead, looking for smaller birds to harass into dropping their catches. The visit is usually a few hours. It is the kind of Galapagos experience that, even after decades of tourism, still rearranges what you expect nature to look like.