Karst on gypsum · Basin

A karst landscape, unique in Europe.

The Ballesteros Lagoon Complex in Cuenca is a karst wetland formed by more than 30 lagoons and dolines on limestone. It is located just 20 minutes from the city, between the municipalities of Arcas, Valdetórtola and Villar de Olalla.

Practical information

Everything What you need to know.

Dates

From November 9 to 13, 2026

Hours

From 16:30 to 20:30

Duration

20 hours (five afternoons)

Place

Casa de la Cultura de Villar de Olalla, Santiago Valverde auditorium. Calle Jesús de Nazareno, 2. Villar de Olalla (Cuenca)

Teachers

Patricia Olivares (Global Nature Foundation) and Joaquín Cuadro (Community Councils of Castilla-La Mancha)

Directed at

Farmers and ranchers

Price

Free, with limited seats

Certificate

De horas, broadcast by the Junta de Comunidades of Castilla-La Mancha

Karst geology

This is how a karst lagoon.

The Ballesteros Lagoons are collapse dolines: circular depressions that form when water dissolves the gypsum in the subsoil and the ground collapses. Gypsum is up to 100 times more soluble than limestone, which is why what takes millennia elsewhere happens here in decades.

Some sinkholes reach 190 m in diameter and 14 m in depth. When several merge, they form a uvala, a larger, irregular depression.

Sinkholes in gypsum

Depressions of great rarity in Europe. Up to 190 m in diameter and 14 m in depth. Geological processes that are still active today.

Two worlds in one

Permanent lagoons (connected to the aquifer) and temporary lagoons (dependent on rain and runoff). Permanent lagoons have water year-round. Temporary lagoons dry up in summer.

The Invisible Prairies

Charophytes form underwater meadows on the bottom of lagoons. 9 species documented: the most diverse community in the Iberian Peninsula.

Singular phenomenon

A laboratory underwater. .

At the bottom of the deepest lagoons, the water lacks oxygen. Unique microorganisms use sulfur to survive, recreating conditions of the primitive Earth. Sometimes they surface and stain the water red, a very rare phenomenon in Spain.