More here.

I got to walk on a fresh hardened flow on my trip there a few years back, near the ocean. My kids and I had to walk a long ways over very rough lava rock to get to a point where actual lava was still spouting from under the hardened surface and flowing into the ocean. Unlike "movie" lava, which is only hot if you actually touch it, the heat from this little glowing stream was oppressive from fifty feet away.

It got dark as we started back. Real dark, real fast. The rough rocks and deep cracks are not something you want to negotiate in the dark. More unnerving was that now that it was dark you could see the reddish glow of the still-liquid mass at the bottom of the cracks beneath us. We weren't on solid rock, but a crust of solid rock over a still-hot and possibly still-liquid underlayer. Eep.

Fortunately we found a group that had been smart enough to bring a flashlight, and attached ourselves to it. No problem.