The Moinhos Velhos Cave, is one of the most important cave systems known in the Portuguese Estremadura Limestone Massif, with about 9 km in extension.

Visiting the Mira de Aire Caves in Portugal is a must for any fan of unique natural wonders. Located only twenty minutes from the city of Fatima, this spectacular underground cave network spreads out over 15km and features thousands of lights illuminating powerful stalactites, stalagmites, and puddles. Guided tours are available to explore the 600m stretch of caves available and despite being mainly in Portuguese, a pamphlet with English information is made available. For those looking for an adventure away from the hustle and bustle of popular tourist spots, Mira de Aire Caves is sure to provide both mystery and joy. So pack your walking shoes and thermal clothing and take the journey to explore one of Portugal's best kept secrets.