Haena Beach on the Big Island was one of my favourite beaches along with the north shore of Kauai. The north shores of all the islands are spectacular, especially during the winter with all the big waves (but this means it can be very windy for camping.)
There is one beach (also a campsite) on the north shore of Kauai, also called Haena (if I remember correctly) which is at one end of the Napali coast. It means that you can make it your base before hiking along the coast, as there are small and big treks along this coast to beautiful waterfalls and beaches that you can only get to by foot. There is a lot of reef off the north shore, which makes for good waves, and also some good snorkeling. We were able to see a whole family of turtles while we were there.
If you go to the Big Island and you find yourself in Hilo - Ken's House of Pancakes is a must. Open 24-hours since 1971 - no lie. It's amazing.
1730 Kamehameha Ave
Hilo, HI 96720
(808) 935-8711
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