Nestled amidst the vast expanse of the Pacific Ocean, the Galapagos Islands stand as a testament to the raw power of the earth and its geological processes. Beyond its iconic landscapes and diverse wildlife, the archipelago harbours a secret world beneath its surface – a network of mysterious Lava Tubes, which most visitors to the Galapagos get to experience at some point during their trip.
What are Lava Tubes and how are they formed?
Lava tubes are caves formed by lava flows from volcanic eruptions. The lava emerges onto the surface of the Earth as a red-hot liquid, typically at temperatures ranging from 700 to 1,200 degrees Celsius.
As the lava flows, it begins to cool and solidify along the outer surface due to exposure to the air or water. However, the interior of the lava flow remains molten, like a river of fire. This creates tunnels of lava – with the outside forming a rocky roof and sides and the inside containing molten lava. This lava flow often seeks the path of least resistance, carving out channels within the solidified crust. These channels gradually enlarge and deepen, eventually forming elongated tunnels known as lava tubes.
These tubes can range from a few meters to several kilometers in length and may have diameters ranging from a few meters to tens of metres!
Over time, the lava tube may become partially or completely buried by subsequent volcanic eruptions or sedimentation processes, creating underground cave networks.
Unique Features of Galapagos Lava Tubes
Venturing into the depths of Galapagos lava tubes reveals a world unlike any other. Stalactites and stalagmites adorn the ceilings and floors, formed over millennia by mineral-rich water dripping from above. Otherworldly formations, such as lava benches and lava curtains, add to the surreal beauty of these subterranean landscapes.
Is there life in Lava Tubes?
Yes! Although there is very little light and limited nutrients, like most caves, lava tubes can have a relatively stable temperature and over time, flora and fauna have found a way to adapt and survive here.. Indeed it’s thought that they play a crucial role in the archipelago’s ecosystem. Here are some examples of life that can be found in Galapagos lava tubes:
i) Microorganisms: various species of bacteria, fungi, and microalgae inhabit the walls and ceilings of lava tubes, often forming thin biofilms or colonies. These microorganisms play crucial roles in nutrient cycling and decomposition, helping to break down organic matter and recycle nutrients within the ecosystem.
ii) Invertebrates: some invertebrate species are well-adapted to the dark and humid conditions of lava tubes. These may include insects such as beetles, spiders, and centipedes, as well as crustaceans like woodlice and amphipods. Some invertebrates may forage for organic matter or feed on other organisms within the lava tube ecosystem.
iii) Cave-adapted Species: certain species of cave-adapted organisms, known as troglobites are also present in Galapagos lava tubes. These specialized organisms have evolved unique adaptations to life in the dark, nutrient-poor environments of caves and lava tubes. Examples may include cave-adapted insects, crustaceans, and even small vertebrates.
iv) Lichen and Mosses: in some lava tubes, particularly those with openings allowing in light, patches of lichen and mosses may be found growing on the walls or floor. These hardy plant species are able to survive in low-light conditions and may contribute to nutrient cycling within the ecosystem.

Examples of well-known lava tubes in the Galapagos Islands
Los Gemelos Lava Tubes (Twin Craters), Santa Cruz Island:
Los Gemelos, also known as the Twin Craters, is a geological formation located in the highlands of Santa Cruz Island. While technically not traditional lava tubes formed by flowing lava, these twin sinkholes are believed to have formed through the collapse of underground lava tubes. They are surrounded by lush vegetation, including endemic Scalesia forests, creating a striking contrast with the barren volcanic landscape.
El Chico Lava Tube, Isabela Island:
El Chico Lava Tube is a relatively small but well-known lava tube located on Isabela Island, the largest island in the Galapagos archipelago. It features a narrow entrance that leads into a dimly lit cavernous space with distinctive lava formations lining the walls and ceiling. The tube extends for a short distance before narrowing and becoming impassable.
El Chico Lava Tube provides an accessible and relatively easy-to-explore example of a lava tube in the Galapagos Islands. It offers visitors the opportunity to experience the unique geology and underground environment of Isabela Island, including the chance to observe lava stalactites, stalagmites, and other volcanic formations up close.
Exploring Lava Tubes
The best way to explore lava tubes is with a Galapagos guide. If visiting lava tubes is an option on your trip, ensure you wear suitable clothing and footwear:
- Clothing: Dress in comfortable, moisture-wicking layers that provide protection against abrasions and temperature fluctuations. Long sleeves and trousers can help shield your skin from sharp rocks and rough surfaces.
- Footwear: Wear sturdy, closed-toe shoes with good traction, such as hiking boots.. Avoid wearing sandals or shoes with inadequate grip, as the terrain inside lava tubes may be uneven and slippery.
Cultural and Historical Perspectives
For centuries, the indigenous peoples of the Galapagos Islands have revered lava tubes as sacred sites, imbuing them with cultural significance and spiritual meaning. Early explorers marveled at their otherworldly beauty, documenting their discoveries in journals and sketches.
Today, lava tubes continue to inspire awe and wonder, serving as a testament to the enduring power of nature and the resilience of life itself. We hope you get to experience them one day!
More from our blog
How and when were the Galapagos Islands formed?
A life changing trip and awakening to our incredible world – a guest’s personal experience