The Glaser mine is the first mining project of Fossum iron works, and the earliest dated iron ore mine in Norway, completed in 1543.
To gain access park at Øygarden west of Fossum. A path leads to the Glaser.
The mine one finds at the top of the ridge is fenced in, but great care should be exercised.
Wonderful hiking terrain to Ulvskollen and further on into Westmarka (West country).
Tourist maps of the area for sale at the touristoffice in Skien.