West of the Ulster valley is the Soisberg Kuppenrhön (Soisberger Kuppenrhön), which lies mainly in Hesse, with elements in the southeast also extending into Thuringia. This region reaches a height of at the Soisberg in the north where the countryside is enclosed by the Seulingswald forest. It reaches even greater elevations in the extreme southeast, where the Habelberg () west of Tann stands opposite to and north of the Auersberg. This natural region is well known for the Hessian Skittles, a striking regular array of high, gently rounded, basalt cones up to . North and south of the skittles most of the kuppen in this natural region are also arranged in a row along the watershed between the Werra and the Fulda and between the Ulster and the Haune respectively. To the west they do not quite reach the Haune at the Haune Plateaux; to the south the Nüst valley below Obernüst forms a natural boundary.