Inside the old church (right beside the modern) in Bø, in the district of Telemark, you can se the tetragrammaton YHWH at the topmost of the altarpiece. There isn’t much light here, so remember to bring a flashlight and a camera with flash. The church is built in the 1100’s, but the altarpiece is probably from the second half of the 17th century.
Here you can see some of the places where you can find God's personal name in Norway.