You MUST go to Hawaii Volcanoes National Park on the Big Island to see Kilauea! Seeing the eruption in the caldera and hiking across a lava field to view the lava at night were the highlight of our vacation. You can't see something like this anywhere else on earth.

Also try to visit the astronomical center at the visitor center on Mauna Kea. We were able to see the craters on the moon with incredible detail. We also saw the moons of Jupiter and were able to make out the stripes on Jupiter.