Sima de Manuel Mozo

Sima de Manuel Mozo is a vertical karst cave (sima) near Villanueva de Alcorón, in the province of Guadalajara, inside the Alto Tajo Natural Park in Castilla-La Mancha, Spain. Cavers regard it as the most frequently visited sima in the whole province, though this is a technical caving destination rather than a casual sightseeing stop.

What does the cave look like inside?

The entrance drops through a short six-metre pitch (P6) before opening onto the site's main feature: a roughly 90-metre shaft nicknamed "Tubo de Aspirinas" (Aspirin Tube) by local cavers. It's a strikingly cylindrical, almost uniform vertical tube that runs the descent in one continuous drop. Around 60 metres down, a pendulum move off the rope gives access to a side branch leading to a further shaft of about 40 metres. Together the two shafts form one of the more dramatic vertical systems in the Alto Tajo karst region.

Who is this cave suited for?

This is a technically demanding sima. Descending it requires full single-rope-technique caving gear — harness, descenders, ascenders, ropes of adequate length — and prior experience with vertical caving. It is not a site for unprepared visitors; the people who come here are almost exclusively organised caving clubs and speleology groups. Serious accidents have occurred at the site in the past, so attempting the descent without proper training and equipment carries real risk.

How do you get to the entrance?

Access runs along the CM-2101 road linking Villanueva de Alcorón and Peñalén. A dirt track branches off near the Refugio de la Zapatilla recreation area and the nearby Sima de Alcorón, leading toward the cave mouth. The entrance itself sits in typical Alto Tajo karst terrain, surrounded by rocky, partly wooded landscape.

What else is worth seeing nearby?

The immediate surroundings belong to the Alto Tajo Natural Park, one of central Spain's most distinctive karst landscapes, shaped by deep river gorges cut by the Tagus and its tributaries. The nearby Sima de Alcorón and the Refugio de la Zapatilla rest area make this corner of the Villanueva de Alcorón municipality a natural gathering point for caving groups exploring the region.

Frequently Asked Questions

Can you visit Sima de Manuel Mozo without caving experience? No. It's a technically demanding vertical cave requiring full rope gear and single-rope-technique skills. Descending without proper training is dangerous.

How deep is the cave? Its main feature is a shaft roughly 90 metres deep, the "Tubo de Aspirinas," preceded by a short six-metre pitch, plus a side branch shaft of about 40 metres.

How do you reach the cave entrance? Take the CM-2101 road between Villanueva de Alcorón and Peñalén, then follow the dirt track that branches off near Refugio de la Zapatilla and Sima de Alcorón.

What else can you explore in the area? The Alto Tajo Natural Park offers extensive karst gorges and other caves and shafts, including the neighbouring Sima de Alcorón — the region is a popular destination for caving clubs from across Spain.