Tremuda NW (5)

A high intertidal rift cave near the SW end of Strabandra (inlet/geo). Fairly level walk inside over some large pebbles. Some fine red and green algal crusts low down on the walls. Entrance 2m wide at base, going up 5m to nearly closed, and as a narrow crack, a further 2.7m. The line is roughly NNE/SSW.

It turns a bit left into two rift branches, W one 5m, E one 7m long. There is an aven above the branch point which goes up 10.4 m and has some intriguing white patches on the ceiling. This ceiling may well be the underside of the Tremuda basalt layer which can be clearly seen from outside, sloping towards the W. It looks as though the aven might extend horizontally either/both N & S.

There is also a small cave above and a little left of the main entrance. Its tunnel may connect to the aven inside, but no light was seen looking up the aven. See photos below.

Notes: Access: By land: from saddle on Strabandra Knap; going S down grassy slope, keeping to E side until you can get onto the ungrassed conglomerate ledge which leads down to sea level. Needs to be in bottom half of the tide. Requires ankle deep paddle to reach fully inside.

Links and Resources:

Not shown on any OS map layer.
Photo 1 shows the west end of the north side of Tremuda. This cave entrance is on left from the larger entrance of Tremuda NW (4) on the right. A fault runs along the N wall of Tremuda and the apparent down-throw is on this (N) side of it, and roughly 10 m. However, the BGS 1:10000 solid and drift map dated 1991 shows the down-throw on the south side of the fault line. If the dip of the conglomerate surface is 20 degrees SW (as it is shown by the same map to be on Tremuda Tongue) then that implies a transverse displacement of something over 30 m ENE on the north side relative to the south side of the fault.
Photo 2 shows entrances to this cave (on left, narrow) and to Tremuda NW (4) on the right. Note that there is a small cave above and a bit left of this entrance.
Photo 3 shows the entrance taken looking roughly SSW, across the end of Strabandra on 25/7/20. Note the upper entrance to a cave in the basalt above and a bit left (E). This may or may not be connected to this cave system.
Photo 4 looking up towards the upper entrance described above (photo 3).
Photo 5 zoomed view; as photo 4.
Photo 6 looking into the cave tunnel - showing the red crust algae (Hildenbrandia rubra) in a narrow band on either side wall. Note than the green algal crust is confined to the immediate entrance, where there is more light available.
Photo 7 shows the inner divide. The left (E) branch adds 7 m and the right one 5m to the 20m of tunnel up to that point.
Photo 8 looking towards the entrance from 20 m inside.
Photo 9 looking up the rift/aven. The white patches are probably a layer of ascomycete bacterial mycelium and also probably the underside of the Tremuda basalt lava flow. It is wide enough to be climbed with suitable equipment. It may be a rather unique exposure.

This entry was last updated: 2026-02-23 16:17:36

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NGR:	NO 88036 83186
WGS84:	56.93979, -2.19825
Length:	32 m
Vert. Range:	11 m
Altitude:	3 m
Geology:	Dunottar conglomerate
Tags:	Cave, Fissure, SeaCave
Registry:	main

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