Kaunaʻoa Bay has one of the few white sand beaches of the Kohala Coast, the western side of the island of Hawaiʻi. A historic hotel, the Mauna Kea Beach Hotel, is located on beautiful Kauna'oa.
The word 'kauna'oa' may refer to a few different things, any of which may have been why native Hawaiians named this beach so: the first definition refers to a thin, orange vine with yellow flowers, (Cuscuta sandwichiana), which is found throughout most Hawai'i (this is the official lei vine of Lanaʻi). However, the second definition refers to a mollusk (Vermetidae), and a third definition refers to a tough seaweed (Galaxaura rugosa).
The bay is accessed via Mauna Kea Beach Drive, just west of state Route 19, Hawaiʻi Belt Road, at 20°0′16″N 155°49′30″W / 20.00444°N 155.82500°WCoordinates: 20°0′16″N 155°49′30″W / 20.00444°N 155.82500°W, about 2.6 miles (4.2 km) south of Kawaihae, Hawaii. A part of the Ala Kahakai National Historic Trail can be hiked north to Samuel M. Spencer Beach Park or south to Hāpuna Beach State Recreation Area. Although public restrooms and showers are available, a limited number of parking passes are available at the resort gate. The beach was named "America's Best Beach" in 2000 by Florida International University professor Stephen Leatherman.