Tremuda NW (4)

A tall, beached or supratidal rift cave at the end of the inlet between Tremuda and Strabandra Knap. S wall is partly Dunottar conglomerate - at least at the entrance. Higher up and further in, the S wall is Tremuda basalt with some flowstone on it. It is also significantly undercut. The N wall is Tremuda basalt, but this is covered by quite thick flowstone, especially near the entrance. A large lump of conglomerate on S side at entrance. Aligned on 48 deg. About 13.4 m W and 17.1 H at 27m in. Estimated internal rise on floor from entrance, 4m ish. A gallery at W end which appeared to add an extra 4 m, but could be a bit longer. The rift is on a fault - see BGS map - which the north wall appears to follow.

The cave is remarkable for having so much flowstone in a basalt cave. And it gives nose to rock access to the contact between the bottom of Tremuda basalt above the top of Dunnottar Conglomerate Formation.

Notes: Access: By land from the saddle on Strabandra Knap ridge, going down a walkable 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. There are quite large boulders to be got over on the way to the entrance.

Length survey by N Feilden 1/5/19. More measurements and photos by NF on 27/2/26.

Links and Resources:

Current OS shows a cave dot.
James Reid in his 'Caves and Birds of Fowlsheugh', Deeside Field, 1927, refers to this cave, which he does not name: "Beside the Cove Heads another cavern has been formed by the sea working along faulting in the rock, where the conglomerate and the porphyrite meet. This cave, which is as big as a small church, is above sea level, and may be approached from the land by a steep path." The Cove Heads is the promontory named Tremuda on the OS map. Porphyrite is now referred to as basalt.
BGS map shows a fault running along the S cliff of Strabandra (inlet) through this cave.
Photo 1 shows the entrance to this cave, on the right, and to that of Tremuda NW (5) more centrally.
Photo 2 entrance from part way down the wave cut platform. The north entrance of Tremuda Subterranean Passage is on the left (S). Note how there is a ledge of conglomerate following the line of contact with Tremuda Basalt above it. This shows that the basalt is eroding faster than the conglomerate. The cliff on the right (N) is basalt and it goes down lower than that on the left (S) of the fault. Taken 11/4/25.
Photo 3 entrance from 15-20 m away. The big lump on the left is conglomerate. Everything else is basalt. 1/5/19
Photo 4 shows the fault brecchia above the cave entrance. 27/2/26.
Photo 5 looking into the cave from a few m. short of roof closure. On the left (S) Dunnottar conglomerate ramping down WSW at about 20 degrees dip. On the right (N) Tremuda basalt following the fault plane. At the end of the conglomerate the beach is 4.3 m wide. A little further in, the width is 16.5 m and the floor to ceiling height is 16.9 m. 27/2/26.
Photo 6 shows the north wall in the narrow part just inside the entrance. The thickest flowstone deposits seem to be here forming vertical ribs. 27/2/26.
Photo 7 shows much of the same part of the north wall, but looking about NNE from about the middle where is gets wide at beach level. The west most Dunnottar conglomerate can be seen lower right. 27/2/26.
Photo 8 shows the outside and fracture side of a piece hammered off the north wall shown in photos 7 & 8. 27/2/26.
Photo 9 the raised gallery at the west end. Taken from about the same place as photo 7. 27/2/26.
Photo 10 the ceiling above the north corner of the raised gallery. There appears to be a trace of the bottom side of the fault brecchia seen in photo 4 at the top of the north wall. 27/2/26
Photo 11 showing the raised gallery at the NW end. It was just a bit too high to scramble up. Note that the rock in the foreground is conglomeratic, while that above is basalt. This conglomerate has rock fragments that are much less rounded than that in the immediate foreground of photo 2. It is probably formed in situ from slightly rounded pebbles which have been cemented together by calcitic flowstone. This may only be a more or less thick surface coating over basalt. 1/5/19
Photo 12 a pile of rock dove guano plus a washed in car tyre. 1/5/19
Photo 13 looking outwards (ENE) towards the entrance from about 15 m inside. The lump on the right is conglomerate. The top slopes down as a continuation of the contact plane between Tremuda basalt above and Dunnottar conglomerate below. There is quite a lot of talus material lying on and somewhat obsuring the top surface of the conglomerate.1/5/19
Photo 14 looking roughly SSE at the lower south wall. It is undercut by about 1 - 1.5 m and coloured a rusty pink. Above the undercut, the rock surface is covered with calcitic flowstone. 27/2/26.
Photo 15 looking roughly NE under the south wall overhang. There is a small triangular patch of daylight coming through the entrance. The ramp (clime-able) of Dunnottar conglomerate can be seen underneath that. The overhang continues to the entrance and then reduces to nothing - except for a roughly 3m wide ¼ hemisphere cavelet on the far side of Tremuda NW(5). 27/2/26
Photo 16 another shot showing apparent layering under the south wall undercutting. 27/2/26
Photo 17 the edge between the vertical south wall above the indercutting. The flake shown in photo 18 was taken from roughly triangular grey bit very slightly right of centre and on the vertical face of the edge. 27/2/26.
Photo 18 rock flake hammered of the edge shown in photo 17. The fresh surface is on the left of the left image. A thin layer of white flowstone can be seen on the top edge. This is obscured by a greenish grey (probably) lichenous layer on the outward facing side. Confirms that it is basalt, perhaps slightly altered on its surface. 27/2/26.
Photo 19 what can be seen if the conglomerate slope on the left of photo 15 is climbed. Outside this cave, looking along the contact between Tremuda basalt above and right (S) with Dunnottar conglomerate below. The joint on which Tremuda NW(5) is formed comes in at right angles and the small cave is entirely beyond it. There is otherwise no undercutting at the bottom of the basalt at bottom right, and none beyond the small cave either. The rocks on the shelf ahead appear to be basalt. 27/2/26.
Photo 20 the small cave mentioned under photo 19. This gives a close look at the contact between the Tremuda basalt above and the Dunnottar conglomerate below. This is the largest of three undercuttings of the basalt outside cave Tremuda NW(4). See photo 21 for the other two. 27/2/26.
Photo 21 shows the west half of the north side of Tremuda. The contact line between Tremuda basalt above and the top of the Dunnottar conglomerate formation is very clear, dipping SW at about 20 degrees. The undercutting shown in the previous two photos can be seen slightly left of the rift entrance just outside this cave. They are less tall but are also above joints in the conglomerate. None of these three joints appear to continue into the basalt. 8/7/20.

This entry was last updated: 2026-03-03 18:30:00

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

NGR:	NO 88029 83188
WGS84:	56.93981, -2.19836
Length:	40 m
Vert. Range:	20 m
Altitude:	7 m
Geology:	Tremuda Basalt, Dunnottar Conglomerate
Tags:	Cave, SeaCave
Registry:	main

Other Sites Within 500m