 The highest point in the west, also the start of the valley, lies on the watershed between the Rhine and Moselle rivers, separating here the catchment areas of the Speyerbach and Schwarzbach.In the east the valley ends at the confluence of the Hochspeyerbach with the Speyerbach.The four medieval castles above the valley, namely Elmstein, Breitenstein, Erfenstein and Spangenberg, guarded the sovereignty of the local territorial lords here for centuries.