Poʻipū
A 4km coastal cliff walk from Shipwreck Beach past ancient sand dunes, sea caves, and a limestone sinkhole to the remote Mahaulepu Beach — one of the least-visited beautiful beaches on the south shore. The trail passes Makauwahi Cave, Hawaii's largest limestone cave, which opens to visitors only on set days — check before planning to go inside. Sea turtles are commonly spotted on the rocky headlands; Hawaiian monk seals rest here occasionally; and in winter humpback whales are visible offshore. Far more interesting than sitting on Poipu Beach and almost no one does it.
Free, no reservation. Start from Shipwreck Beach adjacent to the Grand Hyatt Kauai — walk past the hotel toward the east. The trailhead is at the far left end of the beach. Follow the cliff path east. Park gates close around 6pm; do not drive into the Hyatt unless you are a guest.
Year-round. Best in morning for wildlife sightings and coastal light. Trail follows cliff edges — stay well back in high surf. Some sections sandy and exposed to sun.