While Algar do Carvão is closed the operator shows a lava tube instead; the Gruta do Natal entry is extra. 4.79 from 48 reviews at €45 per person.
In our comparison: #17 of 19 in Terceira, by rating weighted by review volume (see the comparison).
3 options from the operator, described in its own words. Prices are the operator's from-prices per adult for a party of two. Click an option to book it on Viator. Guide languages on every option: English, Spanish, Portuguese.
| Option | What the operator says | From, per adult |
|---|---|---|
| GrutasThe page price | Pickup included | €45 for 2+ people |
| Grutas Solo Traveler | Pickup included | €65 |
| Grutas Private | Pickup included | €75 |
Children from €23 (ages 2 to 12). Option texts and prices come from the operator's listing; prices checked on Viator on 31 August 2026.
96% of ratings with a star breakdown are 4★ or 5★: 46 of 48
Star breakdown of all 48 ratings
Reviewers praise the guides' knowledge and the variety of caves; cave admission requires separate payment.
Written by Guidekin from the 42 most recent English reviews on Viator & Tripadvisor (18 June 2018 to 31 August 2026). Refreshed as new reviews arrive; last checked 7 October 2026.
Reviews are shown as the platforms publish them and removed when they disappear there.
Ratings collected from Guidekin, Viator & Tripadvisor.
It is a very extensive geological formation, resulting from the formation of a lava tube in the interior of the island, included in the Serra de Santa Bárbara and Mistérios Negros Natural Forest Reserve.
30 min · Admission not includedFurnas do Enxofre is located in the parish of Porto Judeu, in the Municipality of Angra do Heroísmo, on the island of Terceira, in the Azores. They constitute a fumarolic field, that is, an area that comprises several outlets of aggressive volcanic gases, at different temperatures, some quite high.
35 minWe will go into a lava tube that is not open for turism so it is all natural, very few people know where it is. you have the option to go in or not.
25 minATT: Algar do Carvão will be closed from Oct 19th 2024 to unkown date as of now, during this period we will be showing a hidden lava tube instead.
On this tour you will visit Algar do Carvão which is classified as a Natural Monument, the Christmas cave, the smoke holes (furnas do enxofre).
The operator's own notes, grouped by topic. Nothing here is added by Guidekin.
The booking form will also ask for: dates of birth, arrival flight or ship details
For a full refund, cancel at least 24 hours before the scheduled departure time.
| Tour | Price | Duration | Rating | Group |
|---|---|---|---|---|
| This tour · #17 of 19 | €45 | 3h–4h | 4.79 (48) | shared |
| Private Terceira Island Full Day Tour | €150 | 7h | 5.0 (257) | private |
| Terceira Island: Full Day Tour | €90 | 7h | 5.0 (75) | shared |
| Wines and Moonshines of Terceira | €139 | 8h | 5.0 (62) | shared |
Ranked #17 of 19 in Terceira by Guidekin score (rating weighted by review volume). Prices here run from €39 to €160, median €85; typical length 5h. 3 of 19 are private. Figures are live from the tour cards; the rubric is our handpicked set, not the whole market. Compare all 19 Terceira