Glymur , with a cascade of 198 m, is the second-highest waterfall in Iceland. It was long regarded as the tallest waterfall in Iceland until being surpassed by a newly measured waterfall near Morsárjökull in 2011.
It is situated at the rear end of the Hvalfjörður. Since the opening of the tunnel under this fjord, most people bypass the area. However, it is a very beautiful part of the Hvalfjörður with some tall mountains and forests.
The river Botnsá runs from the Hvalvatn lake and after a short distance the water falls down alongside the Hvalfell mountain into a steep canyon. The waterfall can be accessed from a parking area at the end of the road. Well-equipped hikers can view the waterfall from marked paths on the east side of the river Botnsá.