Venado Caves

The caves at Venado run about two and a half kilometres into limestone that was a coral reef fifteen to twenty million years ago, and the guided route takes you through around a third of it. This is a wet cave: a stream runs along the floor, you wade through it, and in places the passage narrows enough that you go through sideways or on your knees. There are formations, marine fossils in the walls, and a large bat population, along with cave crickets, spiders and the occasional frog. It is not a show cave with railings and coloured lighting; you come out muddy, which is the point.

What you'll find

• The underground stream - waded along much of the route.
• The squeezes - narrow sections taken sideways or crawling.
• Marine fossils - shells and coral in the limestone walls.
• The bat colony - resident through the system.

When to go

December to April is the dry season; after heavy rain the water level rises and the cave closes, sometimes at short notice. Trips run through the day with a guide, helmet, lamp and boots included. Bring clothes you do not mind ruining and a change for afterwards.

Practical notes

This is not suitable for anyone claustrophobic or with limited mobility: there are genuine squeezes, wading in cold water and low ceilings. The cave closes in high water. Bat guano makes the air unpleasant in places and carries a small histoplasmosis risk. Showers at the entrance are basic. You will be soaked and filthy.

Nearby

La Fortuna is an hour east; Caño Negro is an hour and a half north.