Building blocks from Børsa
The building stones of Børsa in Skaun municipality in Fylke Trøndelag in Norway were measured and described by the historian Gerhard Schøning (1722–1780) around 1770 .
He found three building stones in a row by the sea, two of which were standing and one was lying. He doesn't seem to have done any further research. In 1815 L. Klüver came across five stones in two staggered rows, three in the first line and two in the other. Height and thickness were as described by Schøning. The sea then washed away so much of the coast that the Iron Age stones sank. They were later fetched from the coast and four were placed on the Naustmælen road.