The German-Swiss border begins in at the German-Swiss-Austrian tripoint, located within Lake Constance. The precise location of the border within Lake Constance has never been agreed upon officially. The official Swiss national map of 1938 did mark it, at 47°32′39″N 9°33′49″E﻿ / ﻿47.5442°N 9.5636°E﻿ / 47.5442; 9.5636, but maps made since the 1960s have avoided showing the border in the interior of the lake to reflect the lack of an official agreement.