If you are into hiking in the wilderness, this is day tour is a fantastic option. You will drive from Egilsstaðir in the Eastfjords and then hike for 9–10 hours while enjoying the stunning scenery. This hike is truly a hidden gem!
Landmannalaugar geothermal area is one of the highlights of the Iceland Highlands. There's a large geothermal pool where you can bathe in and various options for outdoor adventures. Unforgettable day tour!
If you are the type that likes adrenaline and you can not sit still you should be able to find something to do from my list￼ of recommendations. I have also mixed in some nice things to do in between the crazy stuff.
Akureyri, the second biggest town in Iceland, has so many things to offer. If you are spending time in this charming town, this article by Dísa—who lived in Akureyri for several months—is a fantastic read.