Double Mouthed Cave (west entrance)

The two entrances are separated by a very massive pillar which has a tunnel behind it, joining the two entrances. The east entrance tunnel is short - estimated at about 7 m, but the west rift tunnel goes some way beyond this tunnel. On 13/9/25 this tunnel was entered near high tide, and after passing a restriction too narrow to use paddles, a tall about 7m wide chamber entered. This has a large patch of flowstone and at least one stalactite on the right, high up. The inlet rift continues with a narrower tunnel on the W side. This may be enterable at 2.0 to 2.5 m ACD tide. There is another rift on the E side which appeared too narrow to enter. The tunnel to the E entrance is upper intertidal and probably not navigable. It contributes to the difficulty of entering the W tunnel by filling and emptying across it as the swell goes up and down.

Notes: Access: by sea only - west from Pennan or Mill Shore, or east from Gardenstown.

No dimensions have been measured. The east entrance is at NJ 83470 66423 as close as can be estimated from photos and Pastmap Aerial, but is subject to revision.

Links and Resources:

Not indicated on any OS map layer.
Photo 1 entrances taken from about NJ 8349 6652 on 19/5/22.
Photo 2 entrances from close taken 14/8/25.
Photo 3 this west entrance taken on 14/5/19 when the tide level was 1.8 m ACD.
Photo 4 west entrance on 14/8/25 when the tide level was 3.3 m ACD.
Photo 5 nearly in this entrance on 14/8/25. Light was seen around to the left - confirming that it joins the east entrance behind the pillar. Looking straight on it appeared that there may be a wider chamber further in. But the swell dissuaded further in exploration.
Photo 6 looking out along the W tunnel from a 7 m wide chamber on 13/9/25.
Photo 7 looking up at a fresh face of conglomerate - presumed to be where a flake has dropped off. 13/9/25.
Photo 8 looking inward (S) and up at the face of the S end of the wide chamber. The inlet rift continues on the left (E) and another, narrower rift on the right. At the top is a large patch of flowstone and there appears to be at least one stalactite - though the poor focus does not help. 13/9/25.
Photo 9 continuation tunnel on the E side. It appeared to be just wide enough to paddle into - if there had been near zero swell. Estimated length - 10 m. 13/9/25. The coloured objects on the left are fishing floats/buoys stuck in the horizontal rift.

This entry was last updated: 2025-09-17 12:21:41

Errors or omissions in this information? Submit corrections/additions/comments for this entry to the registrars.

NGR:	NJ 83453 66427
WGS84:	57.68738, -2.27918
Length:	50 m
Vert. Range:	Not recorded
Altitude:	-1 m
Geology:	Gardenstown Conglomerate Formation - conglomerate
Tags:	Cave, SeaCave
Registry:	main

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