The Þyrill (Thyrill) mountain is situated on the northern shores of the fjord Hvalfjörður. The fjord Hvalfjörður is also known as "Whale Bay" and in the fjord is situated the 197 metres high Glymur waterfall. The islandic name Þyrill means air twirl. The mountain is volcanic origin and belongs to the Hvalfjörður Volcanic Complex.
Flying boat "Consolidated PBY-5 Catalina" over Þyrill mountain.