Frösön is the island in Lake Storsjön that Östersund faces across the water, connected to the city by the Frösö Bridge and also by a railway bridge further south. The island is about 10 km long and has its own character distinct from the mainland city: quieter, greener, with a scattering of historical and natural attractions that make it an excellent half-day or full-day destination. Local buses cross the bridge regularly, but a bicycle is the ideal way to explore.
The island holds the runestone (northernmost in Scandinavia), the Frösön church (a Romanesque church associated with the Christianisation of Jämtland in the 11th century), and the Frösö Zoo with its northern European wildlife. There's also a viewing point near the high point of the island with excellent panoramas over the lake back to Östersund. In winter the island side of the lake can freeze and the views across to the city lights over the ice are memorable. Frösön has been continuously inhabited since prehistoric times — the name comes from the Norse god Freyr, suggesting a pre-Christian sacred status — and that long occupation layers quietly beneath the pleasant modern suburb.