On the way to Þórsmörk (Thorsmork) there is a well hidden canion called Nauthúsagil. We spent a good time there playing with the light entering this canyon or gully. Going all the way up to the waterfall is not for everyone which probably explains why the tourist companies don´t send their buses there. There is a rope and a chain you have to hang on to when climbing besides a small waterfall on the way to the end of the canyon. Once there the combination of the waterfall and the light from above is heavenly.
I really enjoyed going there. It is one of the strangest places in Iceland. The light enters the canyon which reflects on the colorful walls