The coast of Northern Trotternish has long attracted the attention of geologists for two reasons, the first being the intermittent exposures of highly fossiliferous Jurassic strata preserved below the great Tertiary lava plateau; and the second, the striking columnar sills of igneous rock which have been intruded into these Mesozoic beds. Intrusive phenomena unparalleled in Britain may be observed (preferably from the sea) from Holm to Staffin Bay, and in slightly less perfect form round the Aird to Duntulm and Camas Mòr.