An excavated valley in the ancient deposits of the Macizo de los Ajaches. This is a graben-type valley, structurally controlled by normal faults in a NE-SW direction. The existence of these faults has influenced the direction of the eruptive fissure including the cones of Montaña Riscada and Caldera Gritana, since, once the power source of this eruption was found, the fault spread in favour of this, causing a change in the direction of the eruptive fissure. One of the volcanic cones formed during this eruption and its deposits close the valley in the NE sector. In the SW sector, the valley has been decapitated by the erosion of the Ajaches escarpment, although it is also possible to locate the Atalaya de Femés volcano at this end, it is probably also conditioned by the presence of the fault. These processes have led to the closure of the valley, transforming it into an endorheic valley that has been silted up by powerful sandy-clay alluvial deposits.
The main interest of this geosite is of a tectonic type, although there is also a geomorphological, sedimentological, stratigraphic and volcanological interest. Important ethnographic interest, since it is an earth mining area used for cultivation in other areas of the island. There are very good observation conditions and great geological diversity.