These horizons close to the formation boundary are characterised by large and abundant chert nodules which can be found all along the inner stream chamber where they have been left behind after dissolution of the surrounding dolomite.

This is mainly due to the nearby dolomite–quartzite geological boundary where the Allt Smoo stream crosses the impermeable quartzites and sinks on meeting the permeable dolomites.

Several remnant pillars can be seen along the eastern side of the Geodh along with a large section of the previous roof which has been partly buried by the grassy slope (normally covered by rocks spelling out the names of visitors to the cave).

Previous dye-testing has linked an underwater passage to an initial sink point in the Allt Smoo stream about 100 metres (330 ft) upstream from the main waterfall, implying that the cave system is at least twice as long as once thought.

Cave divers from the Grampian Speleological Group have dived this sump for a distance of about 40 metres (130 ft), although large volumes of silt and peat in the water have prevented further exploration.

[6] The cave is located 2 kilometres (1.2 mi) east of the village of Durness and is presently served by a car park, toilets, stairs and walkways.