The 8-mile hole in a Hawaii national park that no one can explain

A dramatic, roughly 8-mile-long fissure system known locally as the Great Crack cuts across a remote portion of Hawaii Volcanoes National Park. The feature is not a single neat split but an extensive network of fractures, fissures and volcanic cones whose main fissure stretches eight miles and whose associated features extend another ten. Sections measure up to 50 feet across and plunge as much as 66 feet - or in one spot an estimated 100 feet - into rubble-filled voids. Scientists attribute the formation to volcanic forces in Kīlauea’s southwest rift zone but cannot say exactly when or how it opened or what lies beneath. The crack is historically significant: an 1823 eruption linked to the area produced one of the fastest lava discharges recorded, surging roughly six miles to the sea at about 25 mph and destroying a coastal settlement.

Public knowledge and official familiarity with the Great Crack are surprisingly limited. The park bought the 1,951-acre parcel containing it in 2018 and has since restricted easy access - roads were washed out and gates locked to protect archaeological resources and limit risky visitation. Former rangers and guides describe only rough, hazardous approaches: a marathon six-hour off-trail route from the Kau Desert Trail that requires a backcountry permit, or a shorter, user-generated GPS path used by experienced hikers. Terrain is disorienting - thick cane grass, unstable lava fields, cairn-only wayfinding - and hazards include volcanic gases, Pele’s hair and extreme remoteness, making the site appropriate only for well-prepared, experienced parties.