Gysinge is a town in the municipality of Sandviken in the county of Gävleborg, Sweden.
It is also the main entry point to Färnebofjärden National Park, established in 1998.
The Gysinge forge was founded in 1668, when Peder Swensson received on April 29 the privileges to create a blast furnace.
The first blast furnace was built in 1670 on what is now hyttbacken, and production of materials for the Swedish army began.
The iron produced was of high quality and was in great demand abroad.