☰Mauna Kea Visitor Information Center

At around 9,000 feet on the slopes of Mauna Kea, the Visitor Information Center runs free stargazing programs on most weekend evenings. The air is thin and bone-cold, and the sky is extraordinary — this is one of the premier stargazing spots on earth. Bring warm layers; the temperature drop from the coast is severe. The summit road continues to 13,796 feet where the world's largest observatories sit, but a rental car isn't rated for the unpaved upper section. Book a summit tour or go with a guide if you want to go all the way up. Either way, don't miss the sunset on the way down.