Los Túneles: the lava aquarium off Isabela

By David Brito, Galapagos Dana Tours · Mindo, Ecuador · Updated 5 October 2026

Ask land-based travellers which single tour was worth the whole trip and the answer comes back, more often than any other, Los Túneles. Off the south-west coast of Isabela, lava flows that ran into the sea froze into arches, bridges and calm channels, and the half-day boat trip through them is equal parts geology and aquarium: glassy water, seahorses, whitetip sharks asleep under the arches, turtles everywhere. If you are building an island-hopping route, this site is the strongest argument for including Isabela.

Key facts

What the place actually is

The name is literal. Lava from the Sierra Negra volcano flowed into the sea, and as the surface cooled the molten rock kept running underneath, leaving tubes; the roofs of some collapsed, others held, and the sea moved in. The result is a maze of black arches and bridges over turquoise channels that the boat threads at low speed. Above the water it is lava, cactus and nesting boobies; below it is a sheltered, shallow nursery. The calm water is the point: it is one of the few headline snorkel sites in Galápagos where current is rarely the story.

The wildlife, ranked

• Seahorses. The Pacific seahorse hangs in the shallows with its tail curled around a branch of coral or a mangrove root, and Los Túneles is the most reliable place in the archipelago to find one. The guides know where they live; look, do not touch.
• Whitetip reef sharks. Dozens rest in the shaded tunnels and under the arches, in a spot the guides call the shark cave, close enough that passing over them becomes routine within half an hour.
• Green sea turtles. Constant, feeding on the algae and surfacing beside the boat.
• Rays. Golden rays in squadrons over the sand, spotted eagle rays passing through.
• Galápagos penguins. The small colony on Isabela’s south coast often fishes in the channels; they are the rarest penguin in the world, with about 2,000 birds, almost all on Isabela and Fernandina.
• Blue-footed boobies nest on the rocks you walk past, and on Roca Unión, the islet most tours circle on the way out.

Season shifts the cast rather than the experience. The warm months (December to May) bring the clearest water; the cool months concentrate the marine life and are when the penguins are most active. Our best time guide has the month-by-month split.

How the morning runs

1. Departure from the Puerto Villamil pier, usually between 07:30 and 08:30, in a boat of up to about a dozen passengers with a naturalist guide. Water taxi to the boat, US$1.50.
2. The crossing, 45 to 60 minutes along the coast, with part of it in open water. If you are the seasick type, take your remedy half an hour before boarding; the morning sea is the calmer one.
3. A first snorkel stop at a sheltered site on the way, where the sharks, turtles and rays are usually first seen.
4. The tunnels: the boat enters the maze, you walk over the lava bridges with the guide, and then snorkel the channels, where the seahorses and the shark cave are.
5. Back in town around 13:00, in time for a late lunch.

Two rules worth remembering: stay two metres from every animal, and follow the guide’s line through the tunnels, because the surge inside an arch is the only real hazard of the day. The park rules sum up the rest.

Fitting it into a route

Los Túneles needs a full Isabela day: ferry from Santa Cruz in the morning (07:00, 2 to 2.5 hours), the tour the next morning, and the ferry back on a later day. That is why our 5-day land-based itinerary and the 7-day version give Isabela at least two nights. It pairs well with the Sierra Negra volcano hike on the other day: volcano one morning, lava aquarium the next.

Cruises almost never visit Los Túneles; it is a day-tour site run from Puerto Villamil, and the yachts that call at Isabela’s south coast visit Las Tintoreras (227 departures on 8 yachts in our schedule), the wetlands and the breeding centre instead. The way to combine it with a cruise is a land stay on Isabela before or after the boat, which we arrange as one booking with the ferries and the hotel.

What to bring

Mineral sunscreen (the only kind allowed), a hat for the boat, a towel, a dry bag for the phone and a windbreaker for the ride back in the cool season. Snorkel gear and a wetsuit are provided; bring your own mask if you have one that fits.

Frequently asked questions

How much does the Los Túneles tour cost?

Around US$150 per person in 2026, including the boat, the guide, snorkel gear, a wetsuit and a snack. Prices vary a little between operators; the boat and the guide matter more than a US$10 difference.

Can you snorkel at Los Túneles if you are a beginner?

Yes. The water inside the tunnels is calm and shallow, and the guides stay with the group. It is the site we recommend to nervous swimmers who still want sharks and turtles.

Are there seahorses at Los Túneles?

Yes, and it is the most reliable site in Galápagos to see the Pacific seahorse. The guides know the spots; a sighting is likely but never guaranteed.

How do I get to Los Túneles?

From Puerto Villamil on Isabela, by boat on a half-day tour. You reach Puerto Villamil by ferry from Santa Cruz (07:00 and 15:00 departures, 2 to 2.5 hours) or by small plane.

Do cruises visit Los Túneles?

Almost never. It is a day-tour site from Puerto Villamil. Combine a cruise with a land stay on Isabela if the tunnels are on your list.

Related reading

The island and its other sites are in the Isabela guide; the town you sleep in is in the Puerto Villamil guide; and the sharks you will swim over are in the sharks of Galápagos.

Sources

• Visitor sites, Galápagos National Park Directorate
• Galápagos penguin, Galápagos Conservancy

Last verified: October 2026