Johannisholm is located in Venjanssjön's southern outlet, Venjans parish, Mora Municipality.

 

The place got its name from the priest and entrepreneur Johan Leufqvist who in 1796 started a glassworks. The glassworks was first located on Sandön due to the silicon-rich sand that was there, but lacked hydropower and was then moved to the place that is today called Johannisholm.

 

Johan Leufqvist ran the glassworks until his death in 1814. In addition to the glassworks, a glass grinding mill, stamping plant, sawmill and mill were established. According to documents from 1825, window glass such as table glass and tableware glass were made both clear and green, and ground glass, bottles and smooth stones were also made.

 

However, the production of tableware glass was not a profit for the glassworks due to far too expensive transport costs, so instead they invested mainly in window glass.

 

In 1840, a smithy was also built at the glassworks, the smithy had 2 hearths, 2 hammers, a manufactory with 5 nail and scythe hammers and a bundle hammer with scissors.

 

The mill was bought in 1844 by Elias Lagerheim, who in 1855 closed down all glass production. The

 

In 1856, Stora Kopparbergs Bergslags AB became the owner of Johannisholm and then also closed the smithy.

Stora Kopparbergs Bergslags AB had long intended to build a power plant dam here, but through lowering of Venjanssjön, the waterfall disappeared and also the plans to build a dam.