Every building has a placard which explains in great detail the origin of the building and the historical context in which it sits. Here, we learned about hydropower. This "gate saw" from Åkra is an actual hydro-powered saw with a blade strung tight on a frame connected to a waterwheel through a crank. Water-powered sawmills first appeared in the late 15th century and gate saws like this became common in the 16th century.