Veteran cavers Peter and Ann Bosted were cruising around their hometown of Hawaiian Ocean View, on Hawaii’s Big Island, a few years ago when Ann spotted a small hole off the side of the road.
It was no more than three feet wide—just big and inviting enough for the couple to pull their car over and try to slink into.
“We had a couple hours to kill,” Peter told me, “so we started surveying, and we found a side passage that turned out to be a lot more mazy than we expected.” Back home, Peter marked the puka, or cave entrance, on a digital map and planned to return later—with the landowner’s permission—to see where the opening might lead.