Pen Park Hole
Southmead, Bristol
A Very Large Cavern

Pen Park Hole is the name given to a large natural cave located on the edge of Southmead in Bristol, not far from Filton airfield and close to Filton Golf Course. The entrance can be found at NGR ST 5852 7921 and is protected by a locked steel lid.

This site has been put together to give better access to information about this unusual and important cave. Although the cave has been known for many hundreds of years, having been first explored as early as 1669, it is, perhaps, not as well known as it should be. Its position, in the midst of a residential area, means that access has to be controlled for safety reasons and the fact that it is located a long way from popular caving area of the Mendip Hills means that it is not often visited by cavers.

About this website

This site gives details of both the history of the cave and its unusual mode of formation. There is a section on the maps and surveys that have been made over the years. It is worth noting that the first of these was the earliest cave survey to be published anywhere in the world, in addition links to further reading and contact details for cavers and others wishing to visit the site.


Since the cave was re-opened by Bristol City Council in 1993, visits have been allowed for cavers and other interested vistors under a leader system. We are grateful to the City Council for generously allowing us continued access to this fascinating cave.

In August 2016, the cave was formally designated by Natural England as a Site of Special Scientific Interest (SSSI) giving it additional legal protection. The designation document may be seen here (pdf). We are grateful for their recognition of the unique nature of this cave. This is first cave SSSI to be notified for many years and is believed to be the first where the biological interest has played a significant role in the process.

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Site last updated December 2023