The karst complex of Ojo Guareña consists of a massive network of over galleries and cavities, not all of which are connected, occupying an area of about 13,000 ha.
The main network consists of fourteen caves that are connected with each other over six different levels of the system.
The most prominent entry point is at Palomera Cave.

Ojo Guareña was formed by the erosive action of the Guareña and Trema rivers, in addition to the Villamartín stream.
These bodies of water run through the lower galleries for most of the year, although during flood season it is possible for the water to enter the higher galleries.
Eventually, they return to the outside through karst springs at Trema, Torquilla, Torcón and Torcona, located on a lower section of Trema River.
The groundwater runs through Ojo Guareña at a speed of 1.5–5 km per day, depending on whether the measurement is made during the drier summer or the flood season.
The groundwater feeds an aquifer located in the hinge of the area's syncline fold.
The karst complex of Ojo Guareña consists of a massive network of over galleries and cavities, not all of which are connected, occupying an area of about 13,000 ha. The main network consists of fourteen caves that are connected with each other over six different levels of the system. The most prominent entry point is at Palomera Cave.
Ojo Guareña was formed by the erosive action of the Guareña and Trema rivers, in addition to the Villamartín stream. These bodies of water run through the lower galleries for most of the year, although during flood season it is possible for the water to enter the higher galleries. Eventually, they return to the outside through karst springs at Trema, Torquilla, Torcón and Torcona, located on a lower section of Trema River. The groundwater runs through Ojo Guareña at a speed of 1.5–5 km per day, depending on whether the measurement is made during the drier summer or the flood season. The groundwater feeds an aquifer located in the hinge of the area's syncline fold.
Ojo Guareña