Giant's Causeway giant among giants. He flees back to Scotland in fright, destroying the causeway behind him so that Fionn would be unable to chase him down. Across the sea, there are identical basalt columns (a part of the same ancient lava flow) at Fingal's Cave on the Scottish isle of Staffa, and it is possible that the story was influenced by this. In overall Irish mythology, Fionn mac Cumhaill is not a giant but a hero with supernatural abilities, contrary to what this particular legend may suggest. In "Fairy and Folk Tales of the Irish Peasantry" (1888) it is noted that,
Geological Exploration of the Fortieth Parallel eight volumes of the Fortieth Parallel Survey: Atlases: Geological Exploration of the Fortieth Parallel The Geological Exploration of the Fortieth Parallel was a geological survey made by order of the Secretary of War according to acts of Congress of March 2, 1867, and March 3, 1869, under the direction of Brig. and Bvt. Major General A. A. Humphreys, Chief of Engineers, by Clarence King, U. S. geologist. More commonly known as the Fortieth Parallel Survey, the survey conducted field work from 1867 to 1872, exploring the area along the fortieth parallel north from northeastern California, through Nevada, to eastern Wyoming.