Algar do Carvão and 7 Things to Do in Terceira - Azores

Algar do Carvão and 7 Things to Do in Terceira - Azores


When Is the Best Time

Terceira and the Acores are famous for the majestic cave Algar do Carvão and Gruta do Natal, and there are more such fascinating places. I like to introduce you to this exciting island, the third biggest of the Azores, with two enchanted rainforest hikes, which reminded me of Tasmania. Also, here, you are able to experience volcanic activity at Furnas do Enxofre. On top of all that, I would like to show you the most beautiful natural seawater pool in Biscoitos and where to have dinner.

Staircase leads down in the cone
Algar do Carvao was the main reason for our visit.

Terceira reveals the history of the Azores' origins and the volcanic activity that is still occurring here. A well-developed network of roads and trails makes it easy to explore these highlights of the unspoiled nature of Terceira. Drive along grass-covered craters and ash hills and walk through lush forests. It takes just a few kilometres or ten minutes, and you end up in this diverse awe-striking beauty of nature. 

The Misterios Negros Trail and a hiker
It looks like Tasmania, but it is Terceira.

Terceira is an excellent island for cave enthusiasts, hikers, and for forest lovers. Are you curious now?

Check out my Table of Contents for my Top 7 recommendations for three days in Terceira and for those who have limited time, my one-day itinerary.

1 Algar do Carvão 

Me overstretching my neck to look up and out of the cave
None of the pictures can capture this jaw-dropping view.

Algar do Carvao in Terceira is one of the top ten places of striking beauty in the Azores. The cave is a Natural Regional Monument and is situated in the heart of Terceira at 550 m above sea level. This cave was first explored in 1893, but it was a big effort to make it accessible to the public in December 1968. 

Opening Hours Algar do Carvao and Gruta do Natal

The entrance house built from volcanic stones
The inconspicuous entrance to the cave.

Limited opening hours so we planned everything around this unique cave. 

  • January-March and October-December: Tuesday, Wednesday, Friday and Saturday
    from 14.30-17.00
  • April-May: daily
    from 14.30-17.00
  • June-September: daily
    from 14.00-18.00

Entrance Fee Algar do Carvão 

Map of the Algar do Carvao - Location of the staircases, lake, cathedral
The stairs and the structure of the cave. Map high resolution

Prices went up in 2023. We bought a combination ticket for Algar do Carvão and Gruta do Natal - cash only! Tickets are only available at the caves. Pretty busy in summer, with a limited number of 150 visitors at a time. You may have to line up for access. 

  • Price single ticket: 10€ and combination 15€
  • Free access for members of the “Montanheiros” who are taking care of the cave.

If you are limited in time, then skip Gruta do Natal, but I highly recommend Algar do Carvão.

A visitor on the staircase and the pit opening
The vent of the volcanic pit has a size of 17x27 m

Through the volcanic vent, we descend into the underworld of Terceira. Algar do Carvão is a beautiful dripstone cave which was developed in two phases by Pico Alto: 5.200-3.700 years ago. The translation of Algar do Carvão means a more vertical cavity in Portuguese, contrary to most of the other caves, which are more horizontal. The entire meaning is “charcoal cave”.

The long concrete tunnel like in a mine
This tunnel is the entrance to Algar do Carvao

From here on, we were flashed for nearly two hours. At the small entrance hall leads a narrow path like in a coal mine to the fascinating lush green, steep vent of an extinct volcano. It is a cool climate in the cave (approx. 14°C) with high humidity of 90%. It drips from the walls and ceilings here, ideal for the mosses, ferns, and stalactites’ growth. I recommend a fleece or a jacket for your visit.

The stairs and the lake in the cave
The staircase ends at the lagoon.

You get spectacular views from the 338 steps, which lead down to the lowest platform near the green lagoon of the cave. There is a handrail, but if you have any mobility issues, it is, unfortunately, too hard to get down. At midday, the sun shines deep into the 45 m cone made of basalt rock, and the sun lets the moss, lichen and ferns sparkle.

The dome-like colourful cathedral
Concerts are held because of the acoustic.

It was such surreal scenery while I stood there with my head completely overstretched. In the shelter of this steep volcanic vent are some endemic ferns, mosses, and insects like spiders or cave-dwelling hoppers, which are hardly found anywhere else or in Macaronesia (Azores, Madeira, Canary Islands and Cabo Verde) only.

Inside the cave with the lake and the stalactites
When you reach the bottom, you are inside the cave.

Down there in the pit are three platforms offering spectacular views deep into the cave and to the lowest point, the crystal-clear green sea in 80 m depth. The crystal-clear green water of this up to 15 m deep underground lake is fed by the rainwater penetrating the cave ceiling. The water level depends on the amount of rain, in summer lower and in the winter higher.

The colourful massive burnt cavities
It looks dome-like at the end.

Gas bubble explosions in the lava flow many thousands of years ago can be seen as massive burnt cavities. On the oldest, highest walls, rare stalactites made of amorphous silica (silicic acid) have been forming for thousands of years. That sounds long, but it is a short time for stalactites, which grow just a centimetre in 100 years.

An information board about Algar do Carvao and the origin
Information panel high resolution

The Algar do Carvão has an excellent acoustic. The upper visitor platforms are also popular for concerts; therefore, this part has often been named the cathedral. Although the cave was quite busy, it was peaceful and quiet in there. All visitors were in awe of this simply breathtaking cave. Algar do Carvão is a Must-Visit place in the Azores. Parking Google Maps Location

2 Gruta do Natal

A visitor group on stairs inside of Natal.
Stairs at the beginning of the cave.

The first guided tour was offered on the 25th of December 1969, therefore, called the Christmas Cave. At the end of the approx. 200 m long, wide main tube is a rock formation that looks like and is called an altar. Annually many residents from Terceira visit the Christmas Eve service. Opening Hours are the same as at Algar do Carvão.

A visitor inside of Gruta do Natal wearing a helmet
Signs are indicating the path.

The entrance of Gruta do Natal is located in an unobtrusive stone house close to Lagoa do Negro and the trailhead of Mistérios Negros. Both are located in the Reserva Natural da Serra de Santa Barbara. Before you access the lava tunnel, you get a helmet for the guided tour provided.

Information are displayed inside the Natal
Information is provided in Portuguese and English.

The tour duration is roughly half an hour, mainly in Portuguese and some sentences in English. However, the cave is illuminated and equipped with information signs in Portuguese and English at the most important sections. 

The different volcanic layers inside Natal cave
The walls in the lower section repeatedly show almost smooth stripes and are evidence that in these areas, the lava flow was particularly fast and carried everything away.

The accessible part for the public is almost 700 m long, 12 m wide, and 7 m high and was formed by a volcanic eruption roughly 12.000 years ago. This cave is flat, and only a few steps lead into it.

A roped-off side branch in Natal cave.
Some side arms of the cave are only entered by researchers.

Although it has the same coloured walls as  Algar do Carvão, inside, it looks utterly different. It is a huge cave system, but plenty of the cave branches are roped off and prohibited from accessing.

A visitor scrambles through the hole
One of the narrow sections.

Wear sturdy shoes or trainers to protect your feet from the rough lava floor. The cave is less humid than Algar do Carvão. Some spots are tight, and you have to scramble through them. In fact, it is not much known about Gruta do Natal. During the guided tour, visitors get a first impression of the volcanic activity responsible for creating the Azores and Macaronesia.

Map of Gruta do Natal
Map high resolution

The ceiling of the lava cave is only a few metres deep therefore, the penetrating rainwater can’t dissolve the necessary minerals to form stalactites and stalagmites.

Parking Gruta do Natal and Misterios Negros Google Maps

3 Mistérios Negros – Rainforest Hike

A woman in the pristine nature at Misterios Negros
This was my favourite hike of all in the Azores.

When we visited Gruta do Natal and Algar do Carvão, we first hiked this two-hour circular trail through the untouched Mistérios Negros area “Trail: PRC1 TER” starting at the Natal Cave.

The narrow and wild track
I don't recommend hiking poles to protect the vegetation better use your hands. 

The magnificent, in some sections challenging trail, leads through the thicket of pristine forests of Azores Juniper, Japanese Cedar, and Cape Myrtle, past small swamp lakes and the hills of the black Mistérios Negros. It is a bit of a climb on an uneven and, in sections, boggy path but absolutely out of a fairytale.

Wooden planks leading above the mud
The muddiest sections are covered with planks.

The muddiest sections are covered with wooden planks or tree stumps. When you reach the street, turn left and walk the last part on the road back to Gruta do Natal and the car park.

The mountain covered with primary rain forest.
Can you see Markus on the narrow forest path?

I highly recommend a rain jacket in your backpack. You are hiking in the heart of Terceira in a nature reserve which is part of the Azores UNESCO Geo Park. This lush rainforest exists because of the huge amount of rain and fog here.

Misterios Negros Info Panel.
Misterios Negros Map high resolution
  • Trail length: 5 km
  • Duration: 2 hours
  • Elevation gain: 100 m

4 Furnas do Enxofre – Fumarole

Furnas do Enxofre Information Board
Information is provided at the parking and trailhead. Info board high resolution

West of Algar do Carvão is this outstanding spot located. It is a great short walk after the cave visit through exceptional local flora and fauna when you approach the sulfuric vents. Furnas do Enxofre is an example of secondary volcanism. The fumaroles are situated in geological faults with a depth of thousands of meters and belong to the volcano Pico Alto. It takes a maximum of half an hour to walk, enjoy and read the information panels - entrance is free – limited parking. Parking Google Maps Location

The steam and the boardwalk
You can smell the sulfur steam springs.

A circular constructed boardwalk leads around the most active fumaroles in the nature reserve. It is prohibited to leave the wooden path for good reasons. The sulfur fumes are toxic, and the surfaces of the springs are still hot, almost boiling. Another reason is that rare endemic plants and peat mosses grow here and need protection. 

Zoom into the steam and a rock with pink moss.
What makes Furnas do Enxofre special is the occurring flora.

The wonderfully colourful sphagnum mosses are everywhere, right next to the boardwalks in the bog Did you know that they never die but keep growing upwards, and the lowest parts just decay? They can store 30 times their dry weight in water, making them a significant water resource. 

A hiker on the boardwalk which leads above the lush vegetation.
Take a closer look to the right and left and enjoy the unique plants.

Furnas do Enxofre is most impressive in the early morning or on cool days. When the outside temperature is still cold, the hot, bright sulfur steam becomes more visible. However, we passed by in the afternoon, and it was fascinating.
Due to the high elevation of roughly 600 m, the area is frequently covered in fog, and you can’t see the sulfur steam clearly.

Terceira One Day Itinerary

Map of the centre of Terceira
Map of the four highlights in high resolution

We combined the first four in one day, all in proximity in the centre of Terceira. First, start with the rainforest walk Mistérios Negros, afterwards visit Gruta do Natal, then continue to Algar do Carvão and in the end, walk around the volcanic Fumaroles of Furnas do Enxofre. Bring water and a sandwich, and enjoy this excellent day in the heart of Terceira.

5 Angra do Heroismo and "Impérios"

View to Angra do Heroismo and beach
The Igreja da Misericórdia - Church of Mercy - The blue church was built in the 18th century on the site of the first hospital in the Azores from the 15th century.

The old town of Angra do Heroismo is an early World Heritage Site from 1983. After the earthquake in 1980, the old centre was rebuilt in record time with the support of UNESCO. It is one of the most beautiful cities in the Azores with a special and colourful charm. Almost every house presents itself proudly and with its colourful facade.

A green and white Imperio in Terceira

Colourful “Impérios” - Holy Spirit chapels or churches can be found in all Azores islands, but  Terceira has the highest number, over 70. Every town or neighbourhood has its own beautifully decorated "Império de Espírito Santo". These kinds of temples welcome the Holy Spirit. Around this custom, magnificent festivals are celebrated by all residents.

6 Lagoinha Forest and Lake Walk

The unique forest at the Lagoinha Hike
A tiny hiker amongst big nature.

This is another beautiful circular trail but a more moderate to difficult hike through the lush vegetation in the nature reserve of Terceira. You get to the trailhead of PRC03TER and parking on a dirt road. Google Maps Location 

Lagoinha Trail leads on wooden planks in sections.
You get rewarded with excellent views from higher elevations.

Also, on this trail are many endemic and native Azorean plants, and it is muddy in sections. The trail is clearly marked, and in some parts, boardwalks and wooden steps have been installed to protect the flora and the soil. 

The lush forest vegetation
Another simply beautiful track in Terceira.

The trail markings are in yellow and right, making it easy to follow the wild and almost seven km long track.

The lake - Lagoinha where the track lead to.
You can't get closer to the lake - it is prohibited.
  • Trail length: 6,8 km
  • Duration: 2 1/2 hours
  • Elevation gain: roughly 400 m

7 Piscinas Naturais Biscoitos – Natural Pools Terceira

Biscoitos natural pools and visitors late afternoon.
The different pools at Biscoitos in the north.

This is an excellent spot for swimming in natural lava pools from May/June until October. During low tide, you are able to swim in several pools close to the rough Atlantic Sea, at high tide, it is safer in the big pool close to the shore. Lifeguards are on duty during the peak season, and a food truck, nice fruit and veggie vendors, restrooms, showers, a restaurant and a café are available.

Diver in the bay at Biscoitos
Also excellent for accessing the sea for diving.

It is also a great spot to snorkel either in the safe pools and also in a protected bay for experienced snorkelers, which is also popular with divers. And best of all, one big pool is possible to access for people with disabilities.

Two snorklers at Biscoitos
The visibility was excellent - That's I with the yellow fins.

The water quality is excellent and controlled annually. Ample of parking for free – Google Maps Location

The sunset with outlines of the lava rocks
The breathtaking sunset at Biscoitos in September.
  • During weekends and afternoons in the summer a bit busy, however, there is lots of space for all visitors to enjoy the stunning scenery.
  • Tip: Don’t go barefoot wear water shoes to protect your feet from the sharp lava rocks.
  • Unfortunately, there is no paradise without pitfalls; the toxic jellyfish the Portuguese Man-o-War can occur here, and we saw three small ones in one of the pools on a windy day.

Restaurant Tip

R3 Restaurant in the east in the evening
The excellent restaurant with indoor and outdoor seating.

Like everywhere in Portugal and so on the Azores, there are plenty of excellent restaurants offering outstanding seafood for an affordable price.

Salad and caramelized onions on bread
My starter

By accident, we had dinner in Restaurant R3 opposite our hotel, and it turned out to be our favourite during our stay in Terceira. R3 Google Maps Location

Hotel Tip

The 4 star Atlantida Mar Hotel at the sea.
I forgot to take a picture of the view to the sea from our room

The 4-star Atlântida Mar Hotel was the perfect choice for our four-night stay in Terceira. We had a spacious room with a kitchenette and balcony with an ocean view. Breakfast was included and absolutely great. The staff was wonderful, and so was the location.

How to Get to the Azores and Terceira?

Sata airline

​Sao Miguel is the central hub of the 9 Azores Islands. It is a two hours flight from Portugal's mainland from Lisbon to Sao Miguel - Ponta Delgada. There are also direct flights from Boston, New York, and Toronto by SATA (Azores Airline) and TAP to Sao Miguel, Pico, Terceira, and Horta available. The direct flights take 5-6 hours. Also from Europe are direct flights offered like from Frankfurt.

Travelling from one island to the next is cheap and easy to handle by ferry or SATA Airlines. SATA offers exceptional service; you can easily change your flight on the Azores without any additional costs, just with a telephone call. Sport and diving equipment is free of charge; it only has to be added to your booking.






These are my recommended tours for the centre of Terceira via GetYourGuide with 24 hours advance cancellation policy. Thx for booking via my website! With your support, I am able to provide all information first-hand. Tour prices are at no extra cost!

Best Months to Visit


Location and Tips

Azores, Terceira

Terceira is the third largest island of the Azores, with 403 km². You can easily circumnavigate the island by car - 80 km on ll-developed roads within two hours. The island has about 55,000 inhabitants.

A heart and written is Terceira in the sand at Angra do Heroismo Beach.
Sometimes a picture is worth a thousand words.

Terceira stands out for its untouched and enchanted forests that can be discovered in the hinterland. In addition, there are two famous caves close to each other, yet not connected.

Mosses and lichen dominate the pristine forests.
The pristine nature of Terceira is simply unique.

Do you want to obtain the usage right for my images? Contact me, but I will take action against picture theft. 

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Created by
Micha Herber-Bleich
Micha Herber-Bleich
I am always open, curious about new…