Pololu Valley opens to the ocean on the north side of the Big Island.  It is about about an hour drive from Kailua-Kona.   You can only hike into the valley as there are no roads.  The hike is about 20 min. down to the water but you can hike across the valley and to the next valley as well and so you can make the hike as long as you wish.    There is no fee to park or enter the valley.   You might want to plan on stopping at the town of  Hawi (link to Hawi )  to see the shops and the statue of the King.   Click on the photo to enlarge.