Mauna Kea

. One unusual trip we recommend is a visit to the top of Mauna Kea. The summit, at over 13,700 feet, is home to the most extensive collection of astronomical observatories in the world. There are several companies that offer organized tours to the summit (the rental car companies do not permit you to take their cars up there). Beginning in mid-afternoon, you end up on the summit for a mind-boggling sunset, followed by an evening of stargazing at an elevation of more than 8000 feet. Helicopter rides to the volcano and the Hamakua Coast also are worth the price.