Avaiki Cave is a large sea cave on Niue's west coast, accessible at low tide via the Avaiki Sea Track near the village of Makefu. The cave is carved into the coral limestone cliffs and opens to the ocean through an archway that fills with sea water at high tide. At low tide, you can walk inside and explore the chamber, which has dramatic stalactite formations and a pool of clear water at the back.
The cave is both geological and cultural — it holds spiritual significance in Niuean tradition and its name connects it to the deepest stratum of Polynesian mythology. The track to the cave requires some scrambling over uneven rock; wear closed shoes. Time your visit to arrive at or just after low tide for the best access. The surrounding cliffs are spectacular, and the cave mouth frames a view of the open Pacific that is hard to forget.