Excavations carried out by Jesse Byock et al revealed the remains of an early church and a Viking hall at Hrísbrú in the Mosfell Valley.
The long-term series of excavations finished some years ago, but the site is still partly visible, having been partly covered. The mound to the rear left of the excavated area is Kirkjuhóll where the church was excavated.
You can find out more about the excavation at: http://www.viking.ucla.edu/mosfell_project/2006_season.html
The site is set in a valley that would have offered a wide range of natural resources.