A spot on the north coast of Caithness, Scotland, 14 miles North of Wick and West of Duncansby Head. It is the mythical site of an octagonal house said to have been erected early in the 16th century by one John Groot, a Dutchman who had migrated to the north of Scotland by permission of James IV. According to the legend, other members of the Groot family followed John, and acquired lands around Duncansby.

When there were eight Groot families, disputes began to arise as to precedence at annual feasts. These squabbles John Groot is said to have settled by building an octagonal house which had eight entrances and eight tables, so that the head of each family could enter by his own door and sit at the head of his own table. Being but a few miles south of Dunnet Head, John o' Groat's is a colloquial term for the most northerly point of Scotland. The site of the traditional building is marked by an outline traced in turf. Descendants of the Groot family, now Groat, still live in the neighborhood. The cowry-shell, Cypraea europaea, is locally known as " John o' Groat's bucky."