11-Day Southern & Western: Post Office Bay's 1793 Mail Barrel

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.

Set in the moist highlands of San Cristobal, this reserve, also known as La Galapaguera, is dedicated to restoring the island's threatened tortoise population. A walk through the grounds takes you past tortoises at every life stage, from hatchlings to full-grown adults, part of the same breeding and reintroduction effort.

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.

A dry landing among the rocks puts you right at the start of one of the richest walks in the islands. The trail follows dramatic cliffs where blowholes send spray high into the air with every swell, and along the way marine iguanas bask on the black rock. Between December and March, the males here turn a striking red and green for the breeding season. Punta Suarez is the only place on Earth where waved albatrosses nest, and between April and December you'll find the colony in full swing, their courtship displays peaking in October. Blue-footed and Nazca boobies nest along the same stretch of cliff, red-billed tropicbirds circle overhead, and the endemic Espanola mockingbird, famously bold, often comes right up to visitors. Keep an eye out too for the Galapagos hawk and the Galapagos dove working the scrub beside the trail.

From the landing, a trail leads to a wide, shallow lagoon where Galapagos flamingos wade through the shallows, filtering shrimp from the mud that gives them their color. Continuing over a low rise brings you to Flour Beach, a nesting ground for green sea turtles between December and June. Just offshore, the eroded remains of an old volcanic cone form Devil's Crown, one of the best snorkeling spots in the islands. White-tipped reef sharks and spotted eagle rays are a near-certain sight inside the ring, and on a good day you might also spot hammerhead sharks, sea lions, or a colorful mix of reef fish weaving through the rocks.

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.

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.

Reachable only by sea, Black Turtle Cove is a mangrove-lined lagoon on Santa Cruz's north shore, protected as a turtle sanctuary. A slow, quiet dinghy ride carries you between four species of mangrove while sea turtles surface for air around the boat, one of the most reliable sightings in the islands. Look down and you'll often see golden and eagle rays moving beneath the hull, and white-tipped reef sharks resting in the shallows.

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 short dinghy ride from Isabela leads to a cluster of small islets ringing a calm, turquoise bay. It connects to a narrow, crystalline crevice where whitetip reef sharks, the tintoreras the site is named for, rest together in daylight, one of the most reliable sightings anywhere in the archipelago. Sea lions, sea turtles, marine iguanas, and rays share the wider bay too, and marine iguanas nest along the islet's edge.

Just outside Puerto Villamil, the Isabela Wetlands are a network of lagoons and mangrove swamp that draw a distinctive mix of shorebirds. White-cheeked pintails, black-necked stilts, great egrets, American flamingos, sanderlings, and more move through these lagoons, making the boardwalk trail through swamp and cactus scrub one of the better birdwatching walks on Isabela.

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.

A zodiac ride along Tagus Cove's cliffs is the first stop, tracing walls carved with the graffiti of sailors and whalers going back over a century. Charles Darwin himself anchored here in 1835. Watch the rock for Galapagos penguins and flightless cormorants before you land and set off on a gently climbing trail, roughly 30 minutes each way, to a viewpoint over Darwin Lake, a crater lake saltier than the ocean itself. Along the way, look for land birds that are easy to miss: ground and tree finches, yellow warblers, large-billed flycatchers, and, with a little luck, the tool-using woodpecker finch. Land iguanas and giant tortoises sometimes cross the path as well. Back at the water, most visits close with a dinghy ride or a snorkel along the submerged cliff wall, depending on the day's plan, with another good chance at penguins and cormorants gliding by.

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.

There's no landing at Punta Vicente Roca: this dramatic, eroded caldera on Isabela's coast is explored entirely by snorkel, dinghy, or kayak. The cold Cromwell Current runs through here, and it's what keeps the water so alive: blue-footed boobies nest reliably along the cliffs, and in the water you can expect Galapagos penguins and, between July and November, ocean sunfish rising to cleaning stations in the cold upwelling. Sperm whales pass through on rare occasions, and giant manta rays are a possibility during the same cooler months.

A quiet landing on Santiago's western coast, best known as a nesting ground for Pacific green sea turtles, who come ashore to lay their eggs between December and June.

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 panga brings you ashore onto one of the most distinctive beaches in the islands, with sand tinted deep red by its high iron content, with Rabida's rugged cliffs rising behind it. Sea lions are usually stretched out along the shoreline, and it's a good spot to watch for the endemic Galapagos dove working the sand nearby. From the beach, a short trail winds through palo santo forest and cactus scrub, climbing gently to an overlook with sweeping views across the bay, a nice place to pause and take in the color of the landscape before heading back down. If you'd rather stay on the water, snorkeling right off the beach is an easy, relaxed way to spend the visit, with good odds of company from the resident sea lions.

Chinese Hat, or Sombrero Chino, is a small islet of delicate lava and spatter cones just off Santiago's southeastern coast. A narrow channel of turquoise water between the islet and the Santiago shoreline makes for excellent snorkeling, where sharks, sea lions, and rays are regularly reported, and a Galapagos penguin occasionally turns up too.

Set on the grounds of the Galapagos National Park Service on Santa Cruz, this station was once home to Lonesome George, the last known tortoise of the Pinta subspecies. A series of interpretive buildings walks you through the conservation science underway across the islands, and the surrounding native vegetation is a good place to look for Darwin's finches going about their business.

The return transfer is straightforward: a panga ride from your ship to the pier, then a short bus ride to Baltra's airport, the world's first fully ecological terminal, run on solar and wind power. Land iguanas, reintroduced here after being wiped out decades ago, are sometimes seen right around the grounds on the way to your flight.