Sima de Alcorón

Sima de Alcorón is a natural sinkhole in Villanueva de Alcorón, in the province of Guadalajara, tucked within the boundaries of the Alto Tajo Natural Park. Carved out over millennia by water eroding the limestone rock, it's one of the most accessible caving sites in the region — visitors can explore it on their own, with no guide and no prior caving experience required.

How do you get there?

The sinkhole sits just off the CM-2101 road, which runs from Villanueva de Alcorón toward Peñalén — at kilometre 4.9 a marked path branches off, leading first to the Zapatilla shelter and then straight down to the sima itself. The drive from Madrid takes roughly two hours, while from the city of Guadalajara it's only about 40 minutes. The site is open around the clock, every day of the week, and there's no entrance fee.

What will you see?

The star attraction is the pozo itself — a natural shaft plunging 63 metres down. The descent is made via 207 steps fitted with a protective railing, though some stretches are damp and can get slippery. The shaft splits into two sections: the first opens onto a platform roughly 20 metres across, lit by daylight pouring in through the wide surface opening. That natural light means most of the cavity can be appreciated without artificial lighting. At the very bottom sits a large pool fed by water trickling down the rock face, forming mineral deposits worth a closer look. A flashlight or headlamp is recommended for this lower section, since daylight doesn't quite reach every corner.

When should you visit?

Midday is the best time to come, when the sun sits high and lights the interior most effectively through the entrance, bringing out the texture of the rock walls. Because the steps are damp and can be slippery, non-slip footwear is a good idea, and warm clothing is worth packing too — the air inside stays noticeably cooler than on the surface, even in summer. The surrounding Alto Tajo park is dotted with dramatic canyons and limestone cliffs, so it's worth setting aside extra time to pair the descent with a walk along the nearby trails.

Frequently asked questions

Do you need caving experience to go down into Sima de Alcorón? No. The descent follows a comfortable staircase fitted with a safety railing, so no climbing skills or caving gear are needed.

Is there an entrance fee? No, the site is free and open 24 hours a day, with no booking or guide required.

What should you bring along? A flashlight or headlamp to light up the lower part of the cave, footwear with good grip for the damp steps, and warm clothing, since it's noticeably cooler underground than outside.

How long does the visit take? The 207-step route itself isn't long, but it's worth taking your time to admire the mineral formations at the bottom — including the walk from the CM-2101 parking area, the whole visit usually takes one to two hours.