Anyone been there yet? It's pretty amazing - lava tubes, sink holes, craters, and other volcanic formations. I've heard the best parts of the park are only accessible by 4wd, but even the car-accessible areas are pretty cool.
We've been there a few times. Our family drove down the east side and hiked in. Once you are in it it's like being on another planet. Another time, my son's scout troop went on the other side and explored some of the caves.