In some places in the Grindelwaldvalley the slopes are in motion: the soft argillaceous schist .in the underground move, influenced by gravity and water slowly toward the valley. The ground glides up to 10 cm per year downhill. The terrain is hilly and cut, which also indicates the movement on the slopes. This slow flowing can cause considerable damage to buildings and infrastructure and requires appropriate strategies. Therefore some of the masts of the cable car First are installed on concrete plinth with rails on which they can be moved if necessary.