Grutas de Santo António and Grutas de Alvados

The Grutas de Santo António and the Grutas de Alvados are two separate show caves close to each other near the village of Alvados, in the municipality of Porto de Mós and inside the Parque Natural das Serras de Aire e Candeeiros. Both are run by the same company, SóGrutas, with one set of prices and a joint ticket. Each visit takes about 25 to 30 minutes with a guide, so doing both makes a manageable morning even for younger children.

They feel quite different, which is the point of doing both. Santo António is all about one enormous room. Alvados is a winding corridor of lakes and very tall shafts.

Two men working near the Pedra do Altar found this cave by chance on 2 June 1955. They were trying to catch a bird, which flew into a large crack in a rock; they followed it in and found the cave. It was the last show cave in the area to be discovered.

The cave covers about 6,000 square metres. The visit starts down an artificial tunnel into a first chamber with a large natural lake. From there a narrow passage opens into the main chamber, which is 80 metres long, 50 metres wide and 43 metres high at its highest point. The Porto de Mós tourism site says specialists and visitors regard it as one of the most beautiful and richest cave chambers in Europe. A natural chimney ventilates the cave, so the temperature stays at about 16 to 18°C.

For children, the size is the thrill: coming through a tight gap into a room tall enough to hold a building is something they remember.

Alvados is made of two parts. The “old cave” has been known for about 400 years and local shepherds used it to shelter from storms. The “new cave”, which is what you visit, was found in 1964 by a group of quarry workers from the Serra dos Candeeiros. They heard stones falling down a shaft (algar) and could tell it was deep. They went down with ropes and torches, and over the next two years tunnels and steps were built so visitors could get in.

The visitable route is 350 metres long. The chambers are up to about 40 metres wide, and the shafts reach up to 95 metres high inside. Alvados is a series of chambers full of stalactites, stalagmites, columns and small lakes linked together. The tourism site describes it as more natural-looking than the bigger Mira de Aire cave nearby, and its corridor shape and very tall shafts make it one of the most characteristic caves in the Iberian Peninsula. It stays at 16 to 18°C all year.

Both caves suit children from about 4 or 5 who can manage stairs. The tours are short, which helps with shorter attention spans. The operator is clear about a few things:

• The route goes up and down 181 steps in all, with slopes and ramps. It’s not difficult, but it isn’t recommended for people with very limited mobility or who need a lot of help.
• They don’t recommend carrying babies or toddlers in your arms, because you need your hands free on the stairs. A back carrier may be an option; ask at the ticket office.
• No animals are allowed in the caves. If you have a dog with you, the operator suggests members of your group take turns.
• Everyone must follow the guide’s safety instructions.

Children who are uneasy in the dark will find the lit chambers and the short tour length helpful. Bring a light jumper, because 16 to 18°C feels cool after a hot day outside.

When we checked in September 2026, the base price for one cave was €8 for ages 12 to 65 and €5.20 for children aged 5 to 11, with seniors over 65 at €6.80. A joint adult ticket for both caves was €11.40. There are cheaper rates for pre-booked school and nursery groups and for groups over 15 people. You can pay in cash, by card (Multibanco) or by cheque on the day.

Families don’t need to book; anyone can turn up and buy tickets during opening hours. Booking is compulsory for school and university groups. The operator suggests everyone books through its website anyway, to help it organise groups.

From September to June, the caves are open 10:00 to 17:00 and closed on Mondays, unless the Monday falls before a national holiday. In July and August they’re open every day, 10:00 to 18:30, with no lunchtime closure. The 2026 exceptions listed when we checked included opening on several Mondays (16 February, 6 April, 4 May, 5 October, 30 November, 7 and 28 December), closing at 15:00 on 24 December and closing on Christmas Day.

There are more show caves close by. Grutas de Mira de Aire is the biggest, and Grutas da Moeda near Fátima is shorter and gentle for small children. For real dinosaur tracks, the Pegadas de Dinossáurios da Serra de Aire are in the same natural park.

Should we visit Santo António or Alvados?

If you only have time for one, Santo António has the single giant chamber; Alvados is a longer corridor of tall shafts and lakes. The joint ticket makes doing both good value.

How long does each cave visit take?

About 25 to 30 minutes each, always with a guide.

Are the caves open on Mondays?

Not from September to June, apart from listed exceptions. In July and August they open every day.

Can we take a baby?

The operator advises against carrying babies in your arms on the 181 steps. Ask about a back carrier.

Can dogs come in?

No animals are allowed inside the caves.