Surtshellir is the longest lava cave in Iceland, located in the Hallmundarhraun lava field. It is situated near the famous Hraunfossar lava waterfalls, and it is freely and relatively easily accessible. This makes it a great combination and a reason why you shouldn’t miss visiting it if you are in the area. There are several entrances to the cave. If you want to fully enjoy and explore it, don’t forget to bring a headlamp! 🙂