Boybuloq Cave
The cave is the deepest known cave in Asia having been explored to a depth of from the entrance. At the lowest discovered level a water-filled siphon blocks further exploration. It is thought that the cave has the potential to be the deepest known cave in the world, with a theorised depth of making it deeper than the Veryovkina Cave. The explored length of the cave is .
North West Highlands Geopark
The area contains a number of limestone caves. The most well known of these is Smoo Cave, a large sea cave near Durness. This cave is unique within the UK in that its outer chamber was formed by the action of seawater, while the inner chambers were formed by fresh water. Its entrance 15 metres high, is the largest entrance of any sea cave in the British Isles. Archaeological excavations have found evidence of human habitation dating back to the Mesolithic period. The cave became well known after Sir Walter Scott visited it in 1814. Another notable cave site is the Inchnadamph Bone Caves. At these caves, remains of Eurasian lynx, brown bear, Arctic fox, reindeer and polar bears have been found; as well as human remains dated between 4,515 and 4,720 years old. Uamh an Claonaite, Scotland's longest cave is partly located below these Bone Caves.