Vierländereck

A quadripoint is a point on the Earth that touches the border of four distinct territories. The term has never been in common use—it may not have been used before 1964 when it was possibly invented by the Office of the Geographer of the United States Department of State. The word does not appear in the Oxford English Dictionary or Merriam-Webster Online dictionary, but it does appear in the Encyclopædia Britannica, as well as in the World Factbook articles on Botswana, Namibia, Zambia, and Zimbabwe, dating as far back as 1990.HistoryAn early instance of four political divisions meeting at a point is in England ; it combined until 1931 the English shires/counties of Gloucester, Oxford, Warwick and Worcester.The earliest known quadripoint involving modern nation states existed from 1817 to 1821 where the present Alabama–Mississippi state line crossed the 31st parallel border between Spain and the United States. During that period, the part of West Florida between the Pearl and Perdido rivers was subdivided and allocated partly to the State of Mississippi and partly to the Territory of Alabama. There resulted, at the intersection of demarcated boundaries, an international quadripoint of four territories, which in the United States were named Baldwin and Mobile Counties of Alabama and Jackson and Greene Counties of Mississippi, though Mobile and Jackson Counties were actually still in Spain.