Gruta do Carvão (that can be translated to the Charcoal cave’) is a unique and fascinating natural wonder that draws visitors from all over the world. This lava tube, which was formed by volcanic activity over 10,000 years ago, is one of the most impressive examples of geological formations in the Azores, and a must-visit attraction for any traveller to the region.
It is the longest lava tube on the island of São Miguel with an extension that goes up to 1,912 meters, although some archive documents report that the tube was much longer than the one we know today.
In this article, we will explore the history, geology, and biology of Gruta do Carvão, and provide tips for visitors to make the most out of their trip to this incredible natural site.
What is Gruta do Carvão?
Gruta do Carvão is a lava tube, which is a type of cave formed by flowing lava. When the lava flows, the outer layer cools down and hardens, while the inner layer continues to flow. As the lava flows through the tube, it leaves behind a hollow space once it solidifies, forming a tunnel-like structure.
Geology & Volcanology
The lava tube of Gruta do Carvão developed in an extensive basaltic flow of 2,500 meters. However, it is not a single cave, but it is divided into several sections: Paím (880,2 m), Tobacco Dryers (701,8 m), João do Rego (287,4 m), and José Bensaude (42,7 m). Those sections are cut by collapsed and obstructed areas, making passage impossible between them. The total area that is explorable is about 1,912 meters long.
Did you know
Old historical reports and explorations relate that Gruta do Carvão once 5-kilometer long.
Gruta do Carvão is located inside the volcanic complex of Picos, an area with around 250 volcanic cones, which is about 50,000 years old.
Gruta do Carvão displays a large variety of geological structures that are typical of effusive volcanism. You can see unique rock formations including lava stalactites, stalagmites and other lava formations like lava balls, lava bridges establishing a link between two walls, ‘balconies’ – the evidence of the lava flows levels inside the tunnel and much more!
Also, amorphous silica stalactites turn some parts of the ceiling orange, due to the presence of minerals like Limonite and Hematite. You will also witness a skylight, a natural opening in the ceiling that allows sunlight to enter. The floor is made of AA lava, an uneven and rough surface, as well as pahoehoe lava (noticeable as small smooth and lightly wavy areas)
History & Geography
This lava tube has been known for a long time thanks to researchers and writers. Indeed, it goes as early as the 16th century with the historian Gaspar Frutuoso referring to Gruta do Carvão in one of its chronicles. It was also mentioned by many physicists and geologists in the 19th and 20th centuries. Gruta do Carvão was even considered as the most remarkable volcanic tunnel of the Azores.
During all this time, the lava tube was home to many scientific studies and it had several uses. For instance, the military thought about the cave as an eventual shelter in case of bombs falling on Ponta Delgada during World War 2. It was also used by the Tobacco factory as a storage place.
Gruta do Carvão extends up to 2.5 kilometres, from the coast of Santa Clara in Ponta Delgada to the emitting centre of lava flows that formed the cave, next to Serra Gorda in Arrifes. Some parts of Gruta do Carvão were discovered by locals doing work in their gardens, and also during the construction of Ponta Delgada’s airport. The cave only opened its doors to visitors in April of 2007.
Fauna & Flora
Gruta do Carvão is home to multiple forms of life. Despite not having any endemic fauna, there are biological communities present in Gruta do Carvão. They adapted to the rough conditions of the caves with a lack of light and high air humidity.
About the fauna, you can spot many birds, mostly at night, such as passers, common blackbirds, and common chaffinches. From time to time it is possible to see dead rabbits because they fall into the cave openings. The lava tube is rich in arthropods (invertebrates) with species like Chthonius ischnocheles, Eidmanella pallida and more.
In terms of vegetation, you can see some roots pending from the cave’s roof. Around the entrances of the lave tube, there are many flora species present like Macaronesian holly, Azores laurel, and many ferns, among other varieties. You can find also many small plants and herbs.
Preservation
The first explorations of Gruta do Carvão began in 1994 by the ecological association Amigos dos Açores. They wanted to focus on this cave because they thought it was of obvious relevance for the speleology assets of São Miguel island. From 1995 to 2006, they had to clean it thoroughly because it was filled with trash, mostly at the entrance points from the ceiling. 22 tons of soil, trash and debris were removed.
Quick Info
In May of 2005, Gruta do Carvão was finally considered as a Regional Natural Monument by the Government of the Azores.
Culture & Festivities
All along the year, Gruta do Carvão hosts many cultural and artistic events such as live music concerts, art exhibitions, and educational workshops. These events are organized by the Regional Government of the Azores, in collaboration with local cultural and educational institutions. This unique place also hosts some alternative events like Sound Healing sessions, or meditation concerts.
Gruta do Carvão is also a popular venue for school trips and educational tours. Students can learn about the cave’s geology, ecology, and cultural history, and provide learning experiences in real life that are both fun and educational.
What To Do At Gruta do Carvão
It is only possible to visit the Paim section of Gruta do Carvão from the Visitor Center in Ponta Delgada. A local guide is also mandatory to explore the lave tube. Please note that it is better to book your tour in advance. There are two types of visits: the short one and the long one.
Do the Short Visit
This visit is of easy access. You will be in a group of a maximum of 15 people, and all will be equipped with a helmet.
Accompanied by a specialist who will tell you everything about this natural wonder, you will discover about 200 meters of the cave for a duration of about 30 to 40 minutes.
Do the Long Visit
This type of visit requires good physical conditions as you will be navigating through rough landscapes and narrow parts of the cave. The route is about 800 meters long and only up to 5 people are allowed to go at the same time.
With the longer visit, you will discover more about Gruta do Carvão, accompanied by a speleologist. You will be equipped with a helmet, headlight, gloves and knee pads. Note that this visit is not available for kids under 10 years old. You also must be in good physical health.
Buy a Souvenir
At the visitor centre, you can find several pieces of art or souvenirs to buy to keep this experience in your memories forever once you get home.
Best Time To Visit Gruta do Carvão
Best Time of the Day
Gruta do Carvão is open to visitors all year round, but the operating hours can vary. Please read the ‘Pricing & Operating Hours’ section for more details or contact the visitor centre.
Plan Your Visit To Gruta do Carvão
How To Get To Gruta do Carvão
The departing point for exploring Gruta do Carvão is located right outside of the agglomeration of Ponta Delgada, next to the highway. When on the highway R1-1A in the direction of Relva, take the exit towards Paim and follow the brown signs indicating the way towards Gruta do Carvão.
You can go there on foot if you are staying in Ponta Delgada, or get a taxi. You can also go on a tour with us to discover this wonderful underworld.
What To Bring To Gruta do Carvão
In order to have a nice and safe visit to Gruta do Carvão, it is necessary to bring comfortable shoes, preferably with a flat and resistant sole. Hiking shoes are good, but avoid city shoes with heels for example.
Inside the cave it can be a bit cold sometimes. Don’t forget to bring a jacket or a sweater, but preferably waterproof as some water can drip from the ceiling and skylight openings.
Where To Eat Near Gruta do Carvão
If you need somewhere to eat near Gruta do Carvão, click here. In this link, you’ll find the 10 best restaurants on Tripadvisor.
Where To Stay Near Gruta do Carvão
To make your life easier, we’ve filtered the search by:
Pricing & Operating Hours
Short visit:
- Children up to 6 years old: Free;
- Children from 7 to 14 years old: 5€;
- Adults from 15 to 64 years old: 8€;
- Students and people older than 65): 5€;
- Residents of the Azores: Free;
- Associates of Amigos dos Açores: Free.
Long visit: 20€.
Opening Hours:
- Open every day 10 am – 12.30 pm and 2 pm – 6 pm.
Book by email (grutadocarvao@amigosdosacores.pt) or by phone (+351 296 284 155 // +351 961 397 080)
If you wish for a complete geo tour of São Miguel island, reach out to Futurismo.
Pro Tips For Gruta do Carvão
Take some warm clothes with you but dress in layers. As you will be walking, you get warmer and might want to take off your sweater.
Don’t forget to book some weeks in advance, because mostly in the summertime, it can get full very quickly.
What To Do Around Gruta do Carvão
Explore Ponta Delgada Municipality
The municipality of Ponta Delgada is the most populous in the Azorean archipelago. Considered by many to be one of the best places to live, this town is full of tourist attractions that are well worth a visit.
Quick Info
Ponta Delgada is 4.5 km from Milícias Beach and Pópulo Beach.
Originally, Ponta Delgada was just a small fishing village. But soon, thanks to its safe bays, it became the most important trading port on the island of São Miguel.
Ponta Delgada was declared a city in 1546 and considered the island’s capital after Vila Franca do Campo was destroyed by an earthquake in 1522. Today, this cosmopolitan city, with approximately 69,000 inhabitants, attracts visitors from all over the world.
Here you can enjoy the sea breeze, the view of the mountains and the delicious local food that is part of the town’s daily life. Here are some of Ponta Delgada’s attractions, such as:
- Carlos Machado Museum;
- City Gates;
- São Brás Fortress;
- Coal Cave;
- Graça Market;
- Atlantic Park;
- Pesqueiro Swimming Pool;
- Sanctuary of Hope;
- Synagogue;
- Among others.
Go On a Whale and Dolphin Watching Trip
The Azores islands are a whales and dolphins paradise! There are about 28 different species of cetacean, with 4 of them resident. This means that you can see those all year round: Sperm whales, Risso’s dolphins, Bottlenose dolphins and Common dolphins.
From March to June, you can see some of the biggest animals in the world passing by the archipelago during their migration. Blue whales, Sei whales and fin whales are quite impressive to watch.
From Ponta Delgada, there are tours every day for whale and dolphin watching. Join Futurismo on a boat excursion to try to spot those amazing animals responsibly. We have marine biologists onboard and respect strict rules of observation for the wellness of the animals.
Hike Rocha da Relva
Rocha da Relva is a village by the water. To go there, you need to do a trail of about 5.5km for up to 3 hours of walking if you decide to go all the way down. It is located about 5 minutes away by car from Ponta Delgada and is a nice place to walk surrounded by nature with a constant view of the Atlantic Ocean.
Down at the village, you will see cute typical houses, some street cats and even donkeys used to bring stuff up and down the trail for the few people living there.
Take a Stroll Through António Borges Park
This historical garden in Ponta Delgada created in 1858 displays plants from all around the world. The highlights are the centennial gigantic trees with roots higher than yourself, the stone caves scattered around the park, and the lookout towers.
It was a private garden until 1950, and now you can visit it for free. There are some ducks at the ponds and even a little café with delicious meals.
Complementary Information
Useful Tools & Apps
The weather in the Azores can be variable, so it’s helpful to use some apps before visiting the islands. Spotazores offers live camera feeds from the main tourist attractions, letting you check the weather and plan your visit. For accurate weather predictions, use Windy or Windguru — they provide the most reliable predictions.
How to Get to São Miguel Island
São Miguel Island is easily accessible with numerous flight routes. Lisbon and Porto are the main entry points to the continent, with direct flights to Ponta Delgada available. To find the best flight, use search engines like eDreams or Skyscanner.
These platforms allow you to compare prices and schedules from different airlines in one place. For more details on how to get to the Azores, look at our guide. Once you find the perfect flight, book it! You’ll reach one of the world’s most beautiful island groups in a few hours.
Best Season to Visit São Miguel Island
São Miguel Island, part of the Eastern Group of the Azores Archipelago, has a unique climate shaped by various factors. This climate fosters the island’s lush vegetation and stunning landscapes. Temperatures stay mild year-round, with only slight variations.
In spring, temperatures average 16 °C, summer peaks at 21 °C, autumn cools to 18 °C, and winter hovers around 14 °C. For more details on the weather in the Azores, take a look at the following links:
- The weather in the Azores in January
- The weather in the Azores in February
- The weather in the Azores in March
- The weather in the Azores in April
- The weather in the Azores in May
- The weather in the Azores in July
- The weather in the Azores in August
Cultural Agenda of São Miguel Island
São Miguel Island hosts a wide range of cultural events throughout the year. The complete list of events is on the cultural agenda!
Video of Gruta do Carvão (São Miguel Island, Azores)
Conclusion
The amazing natural gem of Gruta do Carvão offers its visitors a unique experience. This lava tube formed over 10,000 years ago displays authentic rock formations and is simply fascinating whether you are a geology lover, a history enthusiast, or simply someone who appreciates the beauty of Mother Nature.
A visit to Gruta do Carvão is sure to be a highlight of your trip to the Azores as it holds a significant part in the Azores Geopark. You will better understand the volcanic origins of the islands of the Atlantic. It is one of the most important volcano cavities of the green island.
Gruta do Carvão attracts lots of explorers from all around the globe thanks to its unique characteristics and elements. It is a great place to go and a good alternative for rainy days.
