Arnarfjordur is the second-largest fjord of the Wesfjords and is known as one of the most beautiful of the fjords, due to its diverse landscape, majestic mountains and the breathtaking Dynjandi ('Thunderous') waterfall.
The fjord is 30 km long and 10 km at its widest and features several smaller fjords and inlets. It borders on Slettanes to the north and Kopur to the south.
Between Arnarfjordur and Dyrafjordur lies the Westfjord's highest mountain, Kaldbakur (not to be confused with Kaldbakur in Eyjafjordur), rising to a height of 998 meters. Iceland's national hero Jon Sigurdsson was born in Arnarfjordur, at Hrafnseyri. The fjord also features strongly in folklore, said to have the most monsters of all the country's fjords as well as having many sorcerers.
Also check out Arnarfjörður - the Sea Monster Fjord of Iceland