The western part of Assynt has many distinctively shaped mountains, including Quinag, Canisp, Suilven and Ben More Assynt, that rise steeply from the surrounding cnoc and lochan scenery. These can often appear higher than their actual height would indicate due to their steep sides and the contrast with the moorland from which they rise. Many of the most distinctive peaks such as Suilven were formed during the last Ice Age, when they were left exposed above the ice sheet as nunataks, and they now remain as inselbergs of highly eroded Torridonian sandstone sitting on a bedrock of much older Lewisian gneiss. The Moine Thrust runs through the area, and is most visible at Knockan Crag National Nature Reserve, which includes a visitor centre interpreting the geological features of the landscape. In the east of Assynt lies a region of limestone scenery surrounding Ben More Assynt. This part of Assynt hosts the longest cave in Scotland, Uamh an Claonaite, which lies south of Inchnadamph. The geological importance of Assynt is reflected in its inclusion in the North West Highlands Geopark.