The oldest parts of the Summersberg castle is the round 'Witch Tower' dating from the 14th century. Extensions and additions were made between 15th and 18th centuries. From 1619 to 1828 Summersberg was owned by Counts of Wolkenstein. In 1880 Ignaz Vinzenz Zingerle bought the castle. The descendants of Zingerle still own the castle.
Frösöstenen is the northern-most raised runestone in the world and Jämtland's only runestone. It originally stood at the tip of ferry terminal on the sound between the island of Frösön and Östersund. The stone dates to between 1030 and 1050. It has now been relocated to the lawn in front of the local county seat due to the construction of a new bridge, between 1969 and 1971, on the original site.
Frösö runestone inscription means: Austmaðr, Guðfastr's son, had this stone raised and this bridge built and Christianized Jämtland. Ásbjörn built the bridge. Trjónn and Steinn carved these runes.