Polished underground tours are led by conservationists who emphasize respectful stewardship of these 'living museums.' The geologically interesting caves are accessible to casual visitors during a basic hour-long tour which explores a short, lighted cave section. Enthusiastic guides present Hawaiʻi's cavern-oriented cultural and ecological history. There's also a longer 'crawling' tour ($60) and a two-hour extended twilight tour ($95). Group sizes are kept small, usually with a two- or four-person minimum. Reservations are required.
Children are allowed on most tours (minimum age six or eight depending on which tour). Guides and owners also work to purchase and protect cave access in the region via the Cave Conservancy of Hawai`i (www.hawaiicaves.org).