The Makauwahi Cave (“fear, break through”) is the small portion of the largest limestone cave found in Hawaii. It lies on the south coast of the island of Kauaʻi, in the Māhāʻulepū Valley close to Māhāʻulepū Beach, and is important for its paleoecological and archaeological values. It is reached via a sinkhole and has been described as “…maybe the richest fossil site in the Hawaiian Islands, perhaps in the entire Pacific Island region”.
The pale rock ridge that houses the sinkhole started as a field of sand dunes. Over time, rainwater seeped through the sand, converting it chemically into limestone rock. The sinkhole contains nearly 10,000-years of sedimentary record; since the discovery of Makauwahi as a fossil site, excavations have found pollen, seeds, invertebrate shells and Polynesian artifacts, as well as thousands of bird and fish bones.