The Mauna Kea set the standard for beach resorts when it rose from the sands of pretty Kaunaoa Bay in 1960. Arnie and Jack teed off at the resort's world-class golf course. Today, the swimming and on-shore wave play is some of the best in Hawaii—but the bad news is that public parking is limited and the lot fills up just when you need it.
The 'back door' to Mauna Kea is via Hapuna State Beach, which is just down the coast on this northern end of the Big Island's South Kohala. Hapuna is very popular, but the lot does not fill up.
A recently hewn trail skirts a rugged coastal section for a mile-plus from Hapuna to Mauna Kea. It's a whale-watcher's special in the winter. Non-native vegetation was removed when the trail was built. After leaving Hapuna, the trail passes the green grounds of the Hapuna Prince Resort, and a nice little snorkeling cove complete with a concrete-stair entry.
The route takes you through the site of and the ancient village, Ouli Ahupua'a.
After passing a few new mega-homes, the trail reaches the nice public facilites at the beach. This is a sweet experiece you will want to repeat. Hawaii the Big Island Trailblazer has more details on how to find private, spectacular places.