Fair Head or Benmore (; The Great Cliff) is a long, high, mountain cliff, close to the sea, at the north-eastern corner of County Antrim, Northern Ireland. The cliff's sheer and vertical high dolerite rock face is shaped into distinctive vertical columns like organ pipes, which formed 60 million years ago when a sill of igneous rock was injected between horizontal Carboniferous sediments. Fair Head is considered one of the best traditional climbing and bouldering locations in the British Isles, and is one of the biggest expanses of climbable rock in Northwest Europe. It has one of the largest concentration of extreme-graded routes in the British Isles, and has climbs at E9-grade (e.g. Rathin Effect), as well as highball problems at E9-grade (e.g. Long runs the Fox), and bouldering at grade (e.g. Blondie SDS). Geography The headland of Fair Head rises above the sea, and extends for over . The dolerite rock face is over high in places. Wild goats can be seen roaming among the rocks beneath the clifftops, where a walkway called The Grey Man's Path winds around the rugged coastline. From the road above the cliff, a man-made Iron Age island or crannóg can be seen in the middle of a lake, Lough na Cranagh. The lakes are stocked with trout and can be fished during the summer months. All of the land at Fair Head is private farmland, and not owned by the National Trust (who own the land to the east of the headland). Access is by the goodwill of local farm owners. Fair Head is the closest headland to Rathlin Island. Fair Head's rock formations appear on the 2nd century Ptolemy's map of Ireland from Ptolemy's Geography, described as a point called Ῥοβόγδιον (Rhobogdiun) (cf the Pictish Robogdii tribe), which academics believe is Fair Head. The name may derive from the Proto-Celtic root *bogd, "bend". Fair Head (and the neighboring Murlough Bay) are classed as an area of special scientific interest (ASSI), and are on the register of Antrim ASSI. Geology Fair Head is a sill of Palaeogene age that is the thickest and most extensive of the various sills from the plateau lavas of northeast Ireland. A sill is a tabular body of what was once molten rock that was injected into horizontal rocks (usually well-bedded sedimentary strata). Fair Head's sill is thick at its maximum, and consists of columnar-jointed dolerite rock (a