Sandfell, (743 m) a rhyolite mountain south of Fáskrúðsfjörður.
It is a typical laccolith believed to be 600 m thick and one of the best examples of mountains from the tertier period in the northern hemisphere.
It can be seen very clearly while travelling up the mountain how the basalt layers have been lifted and turned over on its south side while other layers lie untouched beneath it.
This is a nice hiking trail, taking a total of 2–3 hours one way.