The ‘cleft’ in which the building stands consists of two cable-sawn rock faces that are approx. 70 metres long and 15.5 metres apart. The museum building is 11.5 metres wide and is situated at a distance of about two metres from the rock face. Visitors can walk along both rock faces – at ground level on the eastern side, whilst on the western side there are steps leading to the highest point of the hill, where the memorial stone was sited in memory of Petter Dass in 1908.

The exterior steps are reflected in the main staircase leading from the foyer of the building to the exhibitions on the next floor up.