Grutas da Moeda

The cave is in São Mamede, in the municipality of Batalha, just 2 km from Fátima. It was discovered in 1971 by two hunters chasing a fox, which escaped into an algar, a natural shaft in the limestone, in the middle of the woods. Curious, the men climbed in and found galleries full of rock formations. They spent several months exploring before geologists and cavers confirmed that the cave was scientifically interesting. The owners say they have worked to protect the cave and the land around it ever since.

The name comes from a local legend. A rich man walking through the woods was attacked by robbers who wanted his bag of coins (moedas). In the struggle he fell into the shaft, and the coins scattered into the depths and were lost for ever, which is why it was called the Algar da Moeda, the “coin shaft”.

The visitable part of the cave is 350 metres long and goes down to 45 metres below the entrance. Each chamber was given a name suggested by its shapes: the Lake of Happiness (Lago da Felicidade), the Nativity Room (Sala do Presépio), the Shepherd, the Waterfall, the Red Dome, the Maritime Room, the Imperfect Chapel, the Red Vault and the Fountain of Tears (Fonte das Lágrimas). Asking children to spot the shepherd or the waterfall in the rock keeps them looking.

The cave stays at about 18°C all year, so it’s cool in summer and mild in winter.

The cave’s website has a good explanation to share before you go. Caves like this form when rainwater, carrying carbon dioxide from the air and soil, seeps into cracks in limestone. The slightly acidic water dissolves the rock and carries it away, very slowly widening the cracks into tunnels and chambers. About 90% of the work is chemistry and 10% physical forces such as heating and cooling.

Once a chamber has air in it, the dissolved rock is deposited again, drop by drop. Water dripping from the ceiling leaves a tiny ring of calcite that grows into a stalactite. Where the drop lands, a stalagmite builds up from the floor. When the two meet, you get a column. Studies around the world suggest thin tube stalactites grow around 0.3 mm a year. Rough, lumpy “cauliflower” formations cover walls where drips splash. The colours come from iron, magnesium, lead and copper in the water, and from organic matter and bacteria.

The ticket includes the Centro de Interpretação Científico-Ambiental (CICA), a science centre about how caves form, how they connect with the plants and animals of the area, and why limestone matters so much to local life. It also has a large exhibition of minerals and fossils from Portugal and many other countries, and the shop sells minerals and fossils too, which is dangerous territory for young collectors with pocket money. The ticket also includes a tasting of the house liqueur (for adults) and a local cake.

The route is modest in length, which makes this one of the easier show caves for younger children. Under-5s go free. The tour is guided and runs in groups, so children need to stay with the group and keep their hands off the formations. A route that drops 45 metres means steps, and cave floors are often damp, so wear shoes with grip, and ask at the ticket office about buggies and carriers before you go down; the website doesn’t say. Children who dislike dark, enclosed spaces may find it hard, though the lit route and guide help.

When we checked, tickets were €9.50 for adults and €5 for children aged 5 to 12, with under-5s free (proof of age may be asked). There are student and senior rates for groups, and prices for more than 20 people are on request. Online tickets don’t stack with other discounts. After buying, go to the ticket office to validate your ticket for the next available tour.

The cave and the science centre open every day of the year, including Sundays and holidays, except 25 December. Hours are 9:00 to 17:00 in January, February and October to December, 9:00 to 18:00 from March to July and in September, and 9:00 to 19:00 in August. Arrive at least an hour before closing.

The Grutas da Moeda team also runs booked guided walks. One, “Pelos Trilhos da Raposa até à Pia do Urso” (“along the fox’s trails to Pia do Urso”), is a four-hour walk across the São Mamede plateau to the old village of Pia do Urso, which has Portugal’s first sensory eco-park designed for blind visitors. When we checked it cost €18 per adult with a minimum of two adults. There’s also a shorter guided visit to Pia do Urso and its eco-park for €20 per adult. Ask about children’s prices when you book.

The area is full of caves. The biggest is Grutas de Mira de Aire, and the neighbouring Grutas de Santo António and Alvados have one of the most impressive single chambers. Real dinosaur footprints are nearby at the Pegadas de Dinossáurios da Serra de Aire. For a break from rocks, FunPark Fátima is close by.

How long is the Grutas da Moeda tour?

The cave route is 350 metres long and goes 45 metres down. The site doesn’t give a tour time; add time for the science centre and shop.

Are the Grutas da Moeda good for toddlers?

Under-5s are free, and the route is shorter than at the bigger caves nearby. Expect steps and damp floors, and ask about carrying a small child.

Do you need to book?

No. You can buy online or at the ticket office and join the next available tour. Groups of more than 20 should get in touch first.

Are the caves open on Sundays?

Yes. They open every day, including Sundays and holidays, closing only on Christmas Day.

What should we wear?

Something warm enough for 18°C and shoes with grip.