Esa'ala Cave, Natural cave system in Esa'ala District, Papua New Guinea.

Esa'ala Cave is a limestone cave system in Papua New Guinea that descends deep beneath the surface with interconnected chambers and passages. The network spans a vast underground expanse with sections that remain largely unknown to explorers.

Esa'ala Cave lies in the Nipa Basin of Papua New Guinea's Southern Highlands, a limestone region long known to local communities. Systematic exploration by international caving expeditions began in the 1990s, when teams mapped and surveyed the main passages. A fatal accident during a later expedition underscored the hazards of the cave's vertical shafts and flooded sections.

The cave lies in the Esa'ala area of Normanby Island, in Milne Bay Province. Villagers of the surrounding settlements know the entrances and the sinkholes that swallow streams from the surface, and hunters and gardeners use these landmarks when moving through the bush. Knowledge of the passages is passed on by word of mouth rather than written survey.

The cave lies in the Esa'ala District of Milne Bay Province, on Normanby Island in the D'Entrecasteaux group, reached by boat or light aircraft from Alotau. There are no marked trails or lighting inside; parties need caving ropes, helmets and lamps, and should plan for wet, slippery limestone. Local landowners should be consulted before any entry.

Much of the cave network remains unexplored and inaccessible to visitors and researchers alike. The true extent of the underground passages is still largely a mystery.