Treasure: Route BCA

San Cristobal's airport sits at the edge of Puerto Baquerizo Moreno, a five-minute drive from the town center, so this is usually your first taste of the islands rather than a standalone excursion. Sea lions and marine iguanas are known to rest right next to the runway here, an unscripted welcome few airports can match. From the terminal, a short transfer takes you down to the pier for a panga ride out to your ship.

A short landing on one of the most beautiful beaches in the islands brings you into a resident colony of Galapagos sea lions, sprawled across the white sand. Between August and November you may also spot pups nursing nearby. This is one of the only places to see the Espanola mockingbird, found nowhere else on Earth and famously unbothered by visitors. After time on the beach, a relaxed snorkel just offshore is a good way to close out the visit, with spotted eagle rays often gliding beneath the surface.

One of the few places in the islands where human history takes center stage over wildlife. In 1793, a whaling captain installed a wooden barrel here as an informal mailbox, and the tradition has never stopped: you're welcome to leave a postcard without a stamp, and to sort through what's already inside for anything addressed near your own home to hand-deliver in person. After a wet landing on the sandy beach, a short walk brings you to the barrel, then on to a lava tube you can climb down into by ladder. It is one of the most memorable traditions anywhere in the islands.

Formed by geological uplift rather than volcanic activity, Santa Fe is unusually flat for a Galapagos island, and it's the only place on Earth with its own endemic subspecies of land iguana. After landing in clear, turquoise water, a walk through a forest of giant, tree-sized Opuntia cactus leads to iguanas basking beneath them. The Galapagos dove is a reliable sight along the trail, and with some luck you may also spot the Galapagos snake or the Galapagos hawk.

Despite the name, Los Gemelos aren't volcanic craters. They're twin sinkholes, formed when empty underground magma chambers collapsed, set in the misty highlands of Santa Cruz and ringed by dense, endemic Scalesia forest. A trail loops around both rims through some of the lushest vegetation in the islands, one of the better places in the archipelago to spot a short-eared owl hunting in daylight, and, with patience, the increasingly rare vermilion flycatcher.

A small tuff-cone islet just off Santa Cruz's northwestern shore, Eden Islet is explored by panga and snorkel only. The clear, shallow water is a strong bet for green sea turtles, rays, and reef sharks, especially near the mangrove fringe, and blue-footed boobies are often seen diving nearby. Marine iguanas in their reddish breeding colors line the black rock, and a small blowhole occasionally sends spray into the air when the swell is right.

Sierra Negra's caldera stretches 10 km north to south and 9 km east to west, one of the largest volcanic calderas on Earth. The more commonly walked route to Volcan Chico crosses relatively recent lava flows with sweeping views toward the volcanoes of Isabela and neighboring Fernandina; a longer trek reaches a system of active fumaroles known as the Sulfur Mine. This is a geology-and-scenery visit, and wildlife isn't the focus here.

At first glance Punta Moreno looks like little more than a lava flow at the base of Cerro Azul, but its black surface holds a series of lagoons with a surprising amount of life. Flamingos are a fairly good bet in the pools, and paint-billed crakes, white-cheeked pintails, and common gallinules turn up for those willing to watch the water closely.

Fernandina is the only major island in the archipelago with no introduced species, which makes Punta Espinosa one of the most pristine wildlife encounters anywhere in the Galapagos. A wet landing brings you onto black lava draped with the largest gathering of marine iguanas in the islands, alongside Galapagos penguins and flightless cormorants, both drawn here by the cold, nutrient-rich current. Around June, when marine iguana hatchlings emerge, keep an eye out for the Galapagos racer snake hunting along the nesting zone. Snorkeling here is a rare chance to watch marine iguanas feeding underwater, a behavior found almost nowhere else.

Puerto Egas stands out for its black volcanic sand and a shoreline where land and sea meet in close quarters. Galapagos hawks are often seen along the walk, and at the far end waits a colony of Galapagos fur seals tucked into shaded rock grottoes, one of the more reliable places in the islands to see this endangered species.

A relaxed, sandy stop on Santa Cruz's north shore. A lagoon just behind the beach occasionally draws flamingos and other shorebirds, and the beach itself is one of the archipelago's main sea turtle nesting grounds, most active between December and June. It's an easy visit, as much about the swim as the wildlife.

A geology stop first and foremost. A wet landing on a white coral-sand beach leads out onto a pahoehoe lava field that flowed less than a hundred years ago, its surface still holding the ropy, swirled texture it cooled into, a favorite for photographers. Tiny pioneer plants are just beginning to colonize the cracks in the rock. Bring your camera for the landscape rather than your binoculars here.

A wooden staircase of 372 steps climbs Bartolome's extinct volcano from a lava-and-concrete dock or sandy beach, depending on conditions. Along the way, red, orange, black, and even green volcanic layers mark the slopes, home to pioneer plants like the island-endemic Tiquilia nesiotica, lava cactus, and scattered Scalesia. With some luck, a lava lizard crosses the trail. At the top, the view over the twin bays and the iconic Pinnacle Rock is the reward for the climb. Back at sea level, a snorkel around the coral reef and submerged lava rocks is a good bet for Galapagos penguins and white-tipped reef sharks, with sea turtles and manta rays turning up now and then too.

A dry landing sets you down on North Seymour's flat, sun-baked terrain, and the trail wastes no time getting to the action: magnificent frigatebirds display from low shrubs right along the path, males inflating their scarlet throat pouches into balloons to catch a female's eye. Blue-footed boobies are a near-constant presence along the same stretch, and during the breeding season you may catch their high-stepping courtship dance just a few feet from the trail, showing off the bright blue feet that give the species its name. Land and marine iguanas share the coastline as the trail loops back toward the water, and sea lions haul out along the shore. Keep an eye on the cliffs above the surf too, where swallow-tailed gulls sometimes perch between flights out to sea.

Punta Pitt is the only site in the islands where all three Galapagos booby species nest within view of one another: red-foots in the low trees, Nazca boobies on the open cliff-edge ground, and blue-foots further inland. A steep gully climbs to the breeding grounds, where frigatebirds often circle overhead and swallow-tailed gulls round out the colony.

The Galapagos National Park's Interpretation Center on San Cristobal, open since 1998, walks you through the islands' volcanic origins, the evolution of their wildlife, and the conservation work protecting them today, organized chronologically across a series of exhibits. It's a good first stop for context that makes everything you see afterward click into place, a walk-through, education-focused visit rather than a wildlife stop.