Top 11 Lakes around Vegas

The Tierno Galván Park, in San Martín de la Vega, houses an old gravel pit surrounded by interesting vegetation, which belongs to the Jarama wetlands, within the Southeast Regional Park.

The lower basin of the Jarama River is the river axis that links the main elements of the Regional Park of the Southeast. The rich alluvial plains hide 132 artificial lagoons that are authentic distributors of exclusivity and biological diversity. The origin of these valuable wetlands is the extraction of aggregates in the open air, digging enormous holes until breaking the water table and causing the flooding of the gravel pit with water from the river basin. In a short time, the banks of these particular artificial ponds are covered with rushes, reeds, cattails, tamarisks, willows, ash trees and elms, developing leafy belts of marsh vegetation that constitute a magnificent habitat for different groups of aquatic birds, reptiles and amphibians. The gypsum cliffs are also an indispensable environmental element to delve deeper into the surprising natural wealth of the regional park and enrich the aesthetic quality of the landscape. The striking grey and whitish cliffs, with a fragile and arid appearance, are formed by large layers of marl and gypsum sediments piled up during the Miocene while large masses of water containing abundant mineral salts were evaporating. The steep and desolate appearance of these unique reliefs, together with the toxic nature of a substrate rich in calcium sulphate, conditions the development of the plant species that colonize the unstable cliffs, unique and sometimes endemic plants adapted to the demanding conditions in this exclusive geographical section of the park.

The route passes by the Esteras lagoon and ends at the curious ponds of Charcón Grande and Charca Rosa. In some sources, the two ponds appear together under the name Charca Rosa. In any case, they are a unique feature of saline wetlands because sometimes the water appears with a marked pink color. Scientists are investigating the origin of the hue and claim that it may be due to the effect of a microorganism from the saline nature of the water or a halobacteria.

In spring and during the rainy season, the blue surface of the Esteras lagoon is an environmental jewel in the arid landscape of the rural moorland. The volume of water depends on rainfall and evaporation. During long periods of high temperatures, the water disappears and becomes a white salt lake with a noticeable crust of mineral salts. In this case, it is advisable not to enter the lake to closely observe the sodium sulphate crystals because it is a mud trap, the wetland is always under the salt.

It is a small lagoon of endorheic origin that completes the environmental space of the wetlands of the Tajuña valley. The shallow and seasonal nature of the wetland favors silting up and is turning the water patina into a reed bed.

The best times to observe birds are early in the morning, before the birds that sleep in the lagoon go out in search of food, and at dusk, when the birds that spend the day fluttering around the fields and plains of the Tajuña return to spend the night. With luck, suitable equipment, patience and knowledge of the habits of birds, you can see coots, grebes, white-rumped grebes, moorhens, grey herons, mallards, red-crested pochard and various reptiles such as the ocellated lizard and the common grass snake, among many others. In summer, it is easy to observe the bee-eater, little bittern, sand martin, reed warbler, great reed warbler and purple heron in the area around the lagoon and the surrounding steppe mountains.

At this point on the path of La Blanca, at the height of the San Juan lagoons, there is a viewpoint frequented by bird lovers. It is a perfect point to see the fauna that inhabits this seasonal wetland.

The route enters the Cañada del Raso through the access to a gypsum factory, leaves the facilities on the right and passes through the Laguna Seca or Las Esteras wetland, a valuable lake ecosystem in a natural depression in the land that floods temporarily, creating a hypersaline wetland of great geological, botanical and faunal importance of high environmental value, a small wonder in the páramo landscape.