Iceland’s tallest waterfall, is located in Botnsdalur Valley in Hvalfjörður. Glymur is in the river Botnsá that runs out of Hvalvatn, which is a lake closed by molten lava, some 160 metres deep. Standing by the fall you’ll have a good view of the surrounding landcape, which is is particularly attractive, as Hvalfjörður is widely considered one of Iceland’s most beautiful fjords.