On Big Island, Hawaii, there was a time you could walk through the Thurston Lava Tube. Yup, you could walk where lava flowed, creating a tunnel! Most people just kind of walk through it, but looking up shows some of the more creative rock carvings.
The tube is currently closed as it became unstable during the Kilauea eruption in 2018. I was lucky enough to experience it!
(Part of the Image By Andy NFT Collection)