Explore a lava tube made from old volcanoes. I actually think this tour is super underrated, going into this tunnel is SUPER cool. Great for kids (age limit is 3/6+) or a bad weather day where your other tours were canceled. You can just show up, without booking in advance. If you have a chance to the longer more challenging tour, I would definitely suggest that!
Only 40 minutes from Reykjavik! Use code KYANASUE for a discount.