Hike to Brahehus
3 kilometers north of Gränna is the ruin of Per Brahe's hermitage castle, Brahehus. Walk up the mountain, or stop at the rest area.
You can park in Uppgränna and then hike up the mountain. The path is steep, but you will be able to enjoy a great view all the way up. If you want to avoid the hike but still visit the ruin, you can instead stop at the Brahehus rest area by the E4.