Hydrography

Arroyo del Pontón

Upon departing from Villardiegua, the route continues in a southwesterly direction along the right bank of the Arroyo del Pontón for approximately five kilometres until it reaches the Duero River. For most of the year, the Arroyo del Pontón is almost entirely devoid of water, with the exception of periods of heavy rainfall, during which the water flows swiftly through the meadow, greening the surrounding meadows.

Along this path, which is populated by fig trees (Ficus carica), brambles (Rubus ulmifolius) and ash trees (Fraxinus angustifolia), there are 11 water mills, which were once used by the inhabitants of Villardiegua to grind flour.

All the mills are currently in a state of disuse. However, eight have been restored to maintain the cultural heritage of the region, with the grinding wheels and basins being conserved. A multitude of small living creatures converge in the pools created for livestock and in the perennial pools of the stream. These include aquatic insects such as the ditiscus or diving beetle (Dytiscus marginalis) and more complex and unusual animals such as the marbled newt (Triturus marmoratus). The habitats of the cobbler (Gerris lacustris), dragonfly (Orthetrum cancellatum) and mosquito (Culex pipiens) are characterised by high humidity, and these insects complete their life cycles in these environments, which are irremediably linked to water.

As the stream nears its inevitable end, cress and broom (Cytisus scoparius) take over the terrain. Some granitic rocks known as cazoletas can be found close to the riverbank. These items are characterised by a distinctive feature in the form of holes, which were used by the Romans for the purpose of crushing and washing minerals in search of gold, in a manner like that of a mortar. Some bridges, such as the Caozo Llongo Bridge, which allows for crossing the Arroyo del Pontón, are constructed with large stone slabs and are fully integrated into the surrounding landscape.

Although the route deviates from the stream's course and does not follow it to its mouth, at that precise point, the stream has created a natural waterfall that drains into the Duero River during the months of April and May, when the flow is sufficiently low to create a curtain of water. The Pontón waterfall is preceded by several flour mills and can only be accessed from the left bank of the river.