Halmstad Slott was built by King Christian IV of Denmark in the early 1600s, when Halland was still under Danish rule. It was where the Danish king met with Sweden's Gustav II Adolf in 1619 to sort out their issues over decadent meals. (It didn't last.) The castle has since been visited by many Scandinavian royals over the years, including Queen Christina in 1645. The castle is open twice yearly for guided tours in early summer: email for details.