Abismo Oscuro

Dark Abyss Cave

Useful Information

Location: About 12 km South of the capital city of San José, San José province.
Open: Closed.
Fee: Closed.
Classification: SpeleologyKarst Cave
Dimension: L=69 m, VR=24 m.
Guided tours: D=3 h.
Photography: Allowed.
Accessibility: no
Bibliography: Andrés Ulloa, Carlos Goicoechea (2013): Geotourism potential of underground sites in Costa Rica, Tourism and Karst Areas. 6. 43-56. ReasearchGate
Address: FossilLand World Chagers, Tel: 506-2276-6060, Tel: 506-2276-8103, Tel: 506-2276-2665. E-mail: contact
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


2000 film team of Repretel ("The Explorer") rescued from the cave.
OCT-2001 FossilLand opened to the public.
2002 explored by the Asociación Espeleológica Costarricense (AEC).
JUN-2010 surveyed by GEA.
2010 cave added to the FossilLand tourist site.
2020 Fossilland closed.


The Abismo Oscuro (Dark Abyss Cave) is a rather difficult vertical cave, which is used for cave tours recently. The tours are operated by FossilLand, a so-called Parque tematura, a "theme park" offering various outdoor experiences, like canyoning, climbing, driving quad, and even caving. They are located at the farm of Otto von Schroeter. His father came here from Germany to make a living by farming and quarrying the limestone. The current owner has transformed the fantastic landscape caused by this small outcrop of limestone with its rocks and canyons into this new venture. This is on one hand not very good for the environment as the human impact increased. On the other hand the operator keeps the place clean and stopped the quarrying of the limestone.

The Fossil Land Complex is located on a 6 km² big, fossil rich outcrop of limestone and contains six caves. Beneath the caves there are various other karst features. The bioclastic limestone with abundant fossils is of Miocene age (15 Ma). Most common are fossils of Pecten sp., large scallops or saltwater clams which are commonly known as the logo of the Shell oil company.

Abismo Oscuro (Dark Abyss) is also known as Captain Tula's Cave and Patarrá Pit. This cave is pretty small, and actually it's just a 20 m deep shaft with two or three platforms. In 2000 the film crew of the Channel 6 documentary Repretel ("The Explorer") visited the cave. They needed a lot of electricity for their lamps, so they brought their fuel driven power generator into the cave. This was a pretty poor idea as the exhausts of the motor soon filled the cave. Beneath other oxidation products, motors typically produce carbon monoxide, which is a fine way to commit suicide. As a result the film crew had to be rescued from the cave, fortunately there were no casualties.

Today the cave is developed by three long metal ladders. Thus, all visitors who are physically fit and free of vertigo can see the cave, even if they are not familiar with caving techniques. But it is also possible to rappel and climb out using the single rope technique (SRT). The tours into the cave include an introduction into caving and take three hours. Unfortunately the park was closed due to the pandemic, and as a result the cave is also closed. It was not reopened after the pandemic, however, the cave and ladders still exist, so possible it will be reopened by another operator.