Leirdalsheiðarvegur, also known as Road F839, is a rugged 27km drive in Iceland that's only suitable for 4x4 vehicles with high ground clearance. But can be done with 4x4 van or smaller jeep if driven carefully. There're small creek crossings. no large river. Just remember, this road is only open during late summer months, so plan accordingly if you're up for the adventure!

See info on road.is

Note: Check with your rental company if you're allowed to take the car here.

YT video from my trip there : https://youtu.be/D6PucgisMyU?si=-148jwPVrzEEMNGM