The Alviela River Spring is located on the base of a cliff between the national limestone plate region and the lower Tagus tertiary basin. Here, a range of 150 million year old rocks are found together (Jurassic limestone and Tertiary sandstone). The Alviela River presents a permanent and steady flow all year long thanks to its unique water spring. Nonetheless, in periods of heavy rainfall, water is also expelled by temporary restitution points, the most important of all located near the main spring (Olhos de Água) and yet another by the Poço Escuro location. The river flow is strongly influenced by rain water that falls throughout the region’s water basin pertaining approximately 180km2 located in the Santo Antonio Plateau. After the water’s rapid infiltration in the earth, it is conducted by gravity along underground caves that lead to the spring. The Alviela River Spring is one of the country’s most important water spring, displaying water debits of 17L per second: about 1.5 million cubic meters per day. Since 1880 until very recently, this water spring was one of Lisbon’s most important water sources (The Alviela Aqueduct). Today it is still considered as the country’s most important underground water reservoir.
The Caves of Coin Scientific and environmental interpretation Centre (CICA gm) is characterized by being an informative, didactic and scientific space. It is a place where students, tourists and public in general can find answers to the mul ...
The Coin Caves (Grutas da Moeda) are located in São Mamede, municipality of Batalha. Its discovery happened in 1971, as two huntsmen that were chasing a fox, saw it enter by one natural hole under the bushes. Moved by curiosity, they decide ...
The salt-pans can be found 3 km away from Rio Maior, in a valley at the bottom of Candeeiros Mountain. Surrounded by trees, vineyards and other cultivated lands, they are considered a natural wonder, once the sea is about 30 km away. The en ...
Lapas Caves are a network of artificial galleries developed beneath the houses of the village with the same name. This urban area has been raised in a small elevation corresponding to a fluvial terrace of Almonda river, from the Quaternary, ...
The paleontological site of the dinosaurs in Pedreira do Galinha, discovered in 1994, is located in Serra d''Aire. This deposit is one of the most important in the world record, presenting hundreds of sauropod footprints.
Distance: 4.5 km; Duration: 3h; Difficulty: Difficult. Location: Aldeia de Chãos Starting point: Cooperative Parking Terra Chã gps-wgs84 coordinates: 39.417998, -8.920365 The natural park of the Aire and Candeeiros mountains are the most i ...
Circular route starting and ending in the Municipal Park. Mixed floor type, 6 km predominantly on a bike path and about 3 km on a dirt track, from the Health Center to the Marinhas do Sal village. Arriving at the Salt Flats of Rio Maior, y ...
From the geological point of view, the saltworks are located in a diapiric valley. A diapir is a low density rock mass, relatively mobile, crossing other denser rocks. This vertical movement from bottom to top, is made along faults and allo ...
