August 6, 2026 • 7 min read
The volcanic system beneath São Miguel pushes geothermally heated water to the surface across the whole island. In Furnas valley, that means iron-rich thermal pools, steaming caldeiras, and pots of cozido buried underground and cooked by the earth itself. At Ponta da Ferraria, it means a section of the open Atlantic that runs warm year-round. No two sites are the same.
This guide covers every significant thermal site on São Miguel and the one in Graciosa, with practical details on hours, tickets, and what to expect at each.
Furnas: Where the Thermal Activity Concentrates
Furnas is a village inside a volcanic caldera in the interior of São Miguel, about 40 minutes east of Ponta Delgada. The valley floor is dotted with fumaroles and caldeiras, and the sulfuric smell reaches you before the village center does. Three of the main thermal pool sites are within a few minutes of each other here, which makes it easy to combine them in a single day.
One local tradition worth knowing: pots of cozido (a dense meat and vegetable stew) are buried along the Furnas lakeshore each morning and pulled up five hours later, cooked entirely by geothermal heat. Most restaurants in the village serve it daily. Try it here.
Terra Nostra Park
Terra Nostra is the most well-known thermal site in the Azores. The main pool has been in use since 1770 and holds iron-rich water between 35°C and 40°C. The rust-brown color comes from the high iron content, which also stains swimwear permanently: bring dark colors and rinse in cold water immediately after.
Beyond the main pool, there are two smaller jacuzzi-style pools. The grounds include 12.5 hectares of botanical garden with tropical and subtropical vegetation, stone-crossing lakes, and walking paths through mature tree canopy.
Terra Nostra Hotel guests have 24/7 access. The park opens to the general public daily from 10am to 6pm. Book tickets in advance during summer.
6 Nights at Terra Nostra Garden Hotel, Furnas
Flights, rental car, welcome cocktail, and unlimited 24/7 access to the thermal pool — all included. Staying at Terra Nostra puts you at the pools before the day visitors arrive.
See the Terra Nostra package →Poça da Dona Beija
Poça da Dona Beija is a complex of six natural thermal pools, each held at a different temperature between 25°C and 39°C. All pools are shallow, which makes them workable for children and non-swimmers. The setting is beside a river, with dense vegetation on all sides.
One practical detail: the iron deposits on the pool walls function as a natural mineral clay. It is more than a tourist gimmick. Visitors regularly apply it as a facial mask while soaking, and the mineral content is real.
Open daily from 7am to 11pm, with last entry requiring exit by 10:30pm. Visiting at night is worth it if the schedule allows. Buy tickets online in advance, particularly in July and August, when it fills up.
Caldeira Velha
Caldeira Velha is a protected natural monument in the forested hills above Ribeira Grande. The vegetation is dense to the point of jungle. A waterfall feeds directly from the thermal spring into the main pool below, producing a natural hydromassage effect. Two smaller, hotter pools are also on site.
The practical catch: same-day tickets are not available online, and tickets for the following day close at 11:59pm. Book at least one day in advance through the regional parks ticketing platform or you will be turned away at the gate.
Termas das Caldeiras da Ribeira Grande
A smaller and less visited site, housed in a 19th-century building in Ribeira Grande. Three pools total, but only one is open to the general public without a booked spa treatment. The public pool sits in the building's back courtyard, surrounded by walls that bloom with flowers in spring and summer. Less spectacular than the Furnas sites, but quiet, and a good option if you want thermal water outside of the main tourist circuit.
Open daily from 10am to 10pm.
Ponta da Ferraria
Ponta da Ferraria, in the southwest corner of São Miguel, is the only place in the world where a volcanic vent heats a section of the open Atlantic. The natural pool is formed by lava rock on the coastline. Temperature is regulated by tidal flow: at low tide, the hot volcanic water dominates and the pool can be too hot to enter; as the tide rises, cooler Atlantic water mixes in.
The natural pool is free and has no access restrictions on time. The standard approach is to arrive at low tide, test the temperature, and swim progressively toward the open water to find a comfortable spot.
On site, the Termas da Ferraria building operates a restaurant, a spa, and a paid outdoor thermal pool with a more controlled temperature. Useful if the natural pool is too hot on the day you visit.
The rock formations at Ferraria are dramatic and worth the stop regardless of water conditions. This is one of the most visually striking stretches of coastline on São Miguel.
Guided Furnas Valley Thermal Experience
Visit the thermal pools and caldeiras of Furnas with a local Azorean guide. Includes access to Poça da Dona Beija and a stop at the Furnas lakeshore cozido pots.
Book the Furnas thermal experience →Graciosa Island: Termas do Carapacho
Graciosa is the only other island in the Azores with a thermal facility worth the trip. Termas do Carapacho sits in the village of Luz on the island's south coast, overlooking the sea and the Baixo islet. Water temperature holds at around 40°C and is high in magnesium, chloride, and sodium, associated with therapeutic benefits for rheumatological conditions.
The facility includes a covered thermal pool and a nearby outdoor ocean pool with heated water. It is a proper spa setup rather than a wild natural site, and the setting is quiet and intimate in a way that Furnas is not in peak season.
Open Tuesday through Friday from 12pm to 7pm, and Saturday through Sunday from 10am to 5pm. Closed Monday.
Practical Notes
Swimwear: Bring old, dark-colored swimwear. The iron content in the water stains light fabrics permanently. Rinse everything in cold water immediately after bathing.
Jewelry: Leave it at the hotel. The mineral content damages silver and gold.
Hair: If your hair has been recently colored or highlighted, keep it out of the water. The iron content reacts with dye.
Advance booking: Caldeira Velha requires it; no same-day online purchase. Poça da Dona Beija and Terra Nostra are also worth booking ahead in July and August. The Ferraria natural pool is free with no booking required.
Timing: Terra Nostra closes at 6pm. Poça da Dona Beija stays open until 11pm. For both in one day, visit Terra Nostra in the morning and Poça da Dona Beija in the evening.
Rain: A good day for it. The pool temperatures stay constant year-round and the steam is more visible in cool weather.
Pregnancy: Consult your doctor before using any thermal bath.
Azores Vacation Packages Including São Miguel
Complete packages with flights, hotel, and rental car. Furnas is a half-day excursion from Ponta Delgada, so any São Miguel package puts the thermal pools within easy reach.
See São Miguel packages →Frequently Asked Questions
What is the best thermal pool in the Azores? Terra Nostra Park in Furnas is the most well-known, with the largest thermal pool in the archipelago and an award-winning botanical garden on the same grounds. For a more natural experience, Caldeira Velha is the better choice: a waterfall-fed pool in dense forest vegetation. Poça da Dona Beija is the best option for an evening visit, as it stays open until 11pm.
Do you need to book thermal pool tickets in advance? For Caldeira Velha, yes: same-day tickets are not available online and next-day ticket sales close at 11:59pm. For Poça da Dona Beija, online booking is available and recommended in July and August. Terra Nostra is also worth booking ahead in peak season. The Ferraria natural pool is free and requires no booking.
What is the water temperature at Furnas thermal pools? Terra Nostra's main pool holds between 35°C and 40°C. Poça da Dona Beija ranges from 25°C to 39°C across its six pools. Caldeira Velha varies by pool and proximity to the spring. Graciosa's Termas do Carapacho runs at around 40°C.
Can you visit thermal pools in the Azores year-round? Yes. Water temperature stays consistent regardless of season. The pools are a reasonable activity in any weather, and visiting in cooler months or during rain is perfectly fine.
What should you wear to the Azores thermal pools? Dark-colored swimwear you are prepared to stain. The iron-rich water discolors light fabrics permanently. Rinse in cold water immediately after bathing, and leave jewelry and recently colored hair out of the water.
Build Your Azores Itinerary with a Local Advisor
An Azorean travel advisor can build a São Miguel itinerary around the thermal pools, including the best day to schedule Furnas based on your arrival and the weather that week.
