Birseck Castle is located in the municipality of Arlesheim in the canton of Basel-Country. Birseck Castle is also called "Untere Burg Birseck" or "Vordere Burg Birseck" and is one of four castles on a slope called Birseck that confines the plain of the Birs river.
The Eremitage building group that includes the castle is listed as a heritage site of national significance.Burg Reichenstein is the sister castle to Birseck and sits on a higher slope to the north.
Wikipedia https://en.wikipedia.org/wiki/Birseck_Castle
Coordinates 47°29'30.985" N 7°37'42.907" E