Most people who visit Kaua'i don't bother to wander off the beaten path when they're down on WEST side of the South Shore on the way to Waimea Canyon. If they did, they would find Salt Pond Beach State Park, which is next to the Port Allen Airport.
Here's what it looked like on a crappy day in May of 2003. We bought some food in nearby Waimea and drove down to the beach, and had the entire stretch of sand to ourselves, except for the stray helicopter or two taking off from the nearby aerodrome...



