Viking Cave sits at the base of a tall limestone cliff on the northeastern tip of Phi Phi Leh island, accessible only by boat. The cave is active — it is one of the most productive swiftlet nest harvesting sites in the region, with local families holding traditional rights to collect the small white-feather nests used in bird's nest soup. Scaffolding of bamboo poles rises to the cave ceiling, and collection happens at specific times of year.
Boats pull up to the cave entrance and visitors can look in from the water, observing the scale of the operation and the cave paintings on the walls. You cannot go deep inside, but the setting alone — the cliff rising from the emerald water, the dark cave mouth, the sound of swiftlets — is striking. Most longtail boat tours of Phi Phi Leh stop here as part of the circuit that includes Maya Bay and Pi Leh Lagoon.