Gränsö Slott (Gränsö Castle) is a castle located near Västervik, Sweden. The site dates back to the medieval ages. The original castle consisted of a main hall made in wood, which was built in 1807 by Olof Johan Risselskiöld. The castle was extended many times during the 19th century. In 1992, the castle was subject to an extensive renovation. In 1993, when the renovation was nearly finished, a devastating fire destroyed the whole building.