The Mira De Aire Caves rank among Portugal's most captivating hidden gems. This magnificent network of subterranean galleries has become the primary tourist attraction in the Leiria region. You'll find yourself literally at the heart of Portugal's underground wonders.

History

In 1947, approximately 115 kilometers from present-day Lisbon, two villagers strolling through the Leiria mountains stumbled upon an unusual phenomenon. As they ventured higher into the hills, they noticed a mysterious mist continuously escaping from a hole in the ground. Intrigued, they decided to investigate more closely. The opening led to a vast chasm. The two men chose to venture down and take a look. What they discovered were the Mira De Aire Caves—the largest ever found in Portugal.

Later, scientists became fascinated by the peculiar mist emanating from the caves. They sought to unravel the mystery: the subsoil of Mira de Aire is saturated with rainwater, and the temperature inside these caves never exceeds 17°C. The air escaping from below is therefore highly humid, and when it encounters the cold external air, it condenses. This explains the persistent winter mist that emerges during the colder seasons.

Speleologists made the journey from Lisbon to conduct explorations and experiments. The exploration missions advanced steadily.

The Mira De Aire Caves are in fact a gigantic complex of galleries extending nearly 10,000 meters. Following this discovery of major significance, the first explorers of the Mira De Aire underground network co-founded the Portuguese Speleological Society in 1948.

In 1974, the natural museum "Caves Mira De Aire" officially opened its doors to the general public. However, only 600 meters of the galleries could accommodate visitors. Speleologists remained the sole explorers authorized to venture beyond these 600 meters. In 2007, new expeditions led to the discovery of an additional 1,000 meters of galleries. The Mira De Aire Caves now comprise 11 kilometers of underground galleries. Caves Mira De Aire has yet to reveal all its secrets.

Why Visit Caves Mira de Aire?

Caves Mira De Aire has made Avenue Dr Luciano Justo Ramos famous throughout Portugal. This natural museum stands out for the exceptional environment of its underground galleries, offering a unique perspective on cave exploration unlike any other.

The Old Mills Cave

The Mira De Aire Caves can be categorized into three gallery networks:

• the "Gruta dos Moinhos Velhos" (Old Mills Cave),
• the "Gruta da Contenda"
• the "Gruta da Pena".

Currently, only the "Gruta dos Moinhos Velhos" is open to visitors. This cave represents nearly half of all the galleries discovered at Mira De Aire to date.

Ruins of old windmills were discovered on the site. Some of these ruins have been restored and are currently displayed within the cave complex. Fossilized animal bones from the Quaternary period are also exhibited here. The fossils were discovered below the main entrance, likely belonging to creatures that fell into the chasm and never escaped.

The Mira De Aire region has no major river systems. Yet deep within the Old Mills Cave, water pools at the bottom of the abysses of the Serras de Aire and Candeeiros. This is rainwater that accumulates at the base of the galleries. Visitors traditionally toss coins into this natural pool—legend has it this grants wishes.

The Mira de Aire Caves

Contrary to common belief, the gallery walls are fragile. These are limestone formations solidified over time and sculpted by water and moisture for thousands of years. All visitors must be accompanied by a guide, who ensures everyone exercises care and respects the site to avoid damage.

Both summer and winter, the temperature remains constant at around 17°C. The caves' perpetual humidity makes them an ideal natural wine cellar. This consistent humidity favors maturation and preservation. You can admire the wine cellar of the "Galeria do Polvo," where Portugal's finest red wines are stored.

The gallery pathways are illuminated by lamps along walls and staircase, allowing you to photograph sculpted rock faces, rainwater pools reflecting the lighting, and stalactites hanging like chandeliers from the ceiling. You'll also be amazed by the "Sala Grande" (Great Hall)—the largest chamber in the entire underground system, reaching heights of 10 to 30 meters.

Mira De Aire sits directly along the Porto-Lisbon route, making it accessible by train, bus, and taxi.

Other Important Information

Visits to the Mira De Aire Caves are conducted entirely on foot. The circuit spans 600 meters total. A total of 683 staircase steps have been installed to facilitate navigation. At the end of your visit, two large elevators await to bring you back to the surface.

Additional details:

• Address of the Caves Mira De Aire natural museum: Av. Dr. Luciano Justo Ramos, 2485-050, Mira de Aire
• Temperature inside the caves never exceeds 17°C and the air is humid. Be sure to bring appropriate clothing.