On a small peninsula jutting into Hvalfjordur lies the remains of a US and British WWII naval installation. Not much actually survives, just the twisted remains of a steel pier and a few concrete buildings, but this was a fairly sizeable installation (along with the British based in Hvammsvik), dedicated to building and maintaining the anti-U-boat nets and mines protecting the merchant and military convoys along the coast of Iceland.
Hvitanes, on the small point of land, was the British base, with 250 buildings and a veritable town including a cinema, workshop, housing, lighting, heating, and everything a small town needs. The pier was built to load and offload the nets and equipment for the barriers, and in some cases for lading ships, although they normally were anchored across the fjord.
The nearby bay (Hvammsvik) is protected, and the American base was located there. A floating dry-dock, ship repair workshops, ammo storage and the like were located there. Warships anchored in the fjord, waiting to escort merchant and military ships on the routes to Russian ports. German aircraft often patrolled the shores of Iceland; 4 of them were shot down by American pilots during the war.