Speilsalen () was a natural glacier cave formed by a river underneath a glacier in the Trollheimen mountains in Oppdal Municipality in Trøndelag county, Norway. It was located at the northeast base of the mountain BlÃÂ¥høa.
Under favourable conditions late summer, it was possible to walk the from one end to the other underneath the glacier. It was never considered safe to walk under a glacier. Speilsalen collapsed in August 2007.