There is a group of three is a simple passage tombs in Rondossec. The southern dolmen is a smallest, partly collapsed. The central wedge-shaped dolmen has a 6-metre chamber with engravings. The northern dolmen has an 11-metre long passage and a small side-chamber. Gold necklace, vases and stone axes were buried in the dolmen.References:
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.