Outlier mountains are a window into the geological past: erosion has isolated a single mountain from the aggregate to which it originally belonged. Such outlier mountains are to be observed in cuesta landscapes. Such a landscape consists of alternately stored layer packages of weathering and erosion resistant ("hard") and much less weathering and erosion resistant ("soft") rocks. The resistant rocks, also known as step formers, form steep steps, while the less resistant rocks (pedestal formers) form shallow-wave landscapes in front of the steps. In outlier mountains, the flat but steeply shaped cap from the step former protects the less resistant rocks of the pedestal former from erosion. An outlier mountain testifies that the layer of the step former originally existed beyond the level of the layer. Two small outlier mountains are preserved in front of the southern layer of the Luxembourg sandstone near the village of Bech.