I sugest you the night hike to see the lava flow in the east rift zone of the Kilauea. It was one of the most impressive things I´ve ever seen im my life. It is a short hike from the ranger station on the end of the chain of craters road.

Look at http://www.nps.gov/havo/planyourvisit/lava.htm for up to date information about this hike.