Asheberg is a town in Aedirn that first appears on a map of the Pontar Valley in The Witcher 2: Assassins of Kings. There is bridge across the Dyfne river.
Geralt decisions will have an influence over the question whether the city becomes part of Saskia's Free Pontar. Otherwise Kaedwen will annex it together with the rest of the valley.
There are several places in Germany and Austria with the name Aschberg.