This high-clearance 4WD road crosses enough ʻaʻa (rough, jagged type of lava) to shake your fillings loose. However, once only for adventurers, these remote black- and green-sand beaches with looming cliffs and cinder cones are no longer human-free pockets. You may find, after all the trouble of getting here, that the sea is too rough to swim and the beach too windy to enjoy. Even so, this trip into the volcanic 'great beyond' is enjoyable for the scenery alone.
To find the Road to the Sea, turn makai (seaward) off Hwy 11 at the row of mailboxes between Miles 79 and 80 (look for the old 'Tiki Mama' sign painted on a surfboard). From there it's 6 miles of rudimentary, seemingly never-ending lava which most high-clearance vehicles can handle, but you'll want 4WD at Mile 3.1 where the road drops off a lava bench. It takes about 45 minutes or so to reach the first green-sand beach, depending on how rough you like your ride.
Another 0.5 miles to the east (hike it unless you have a rock-crawler) an incongruous tree provides shade over a bleached coral beach. To the west, a series of littoral cones (mounds of tephra formed as hot lava explosively boils in to the ocean), coves and fishponds provide unending coastal exploration. To get here, head back inland to the yellow gate (now on your left) – which we are assured is for emergency closures only, not to limit access.
Less than 1 mile beyond the gate, you'll reach a red puʻu (hill) hiding the crescent green-, black- and white-sand beach where sea turtles frequently nest. The historic Ala Kahakai National Historic Trail continues west to Awili point, one of a scarce handful of places in Hawaii where the Olive Ridley sea turtle (Lepidochelys olivacea) has nested, and the site of a record-setting ulua (giant trevally fish) take: 23 in one night.
Bring as much water as you can carry, because it can be a mercilessly hot and shadeless walk in any direction. Every direction recommended.