Riri Blue Hole

The Riri Blue Hole is a freshwater river cave system near Luganville where a crystal-clear jungle stream passes through a series of submerged caverns before meeting the sea. The water is an extraordinary electric blue caused by the refraction of sunlight through fresh water free of suspended particles, and visibility routinely exceeds 30 metres in the shallower freshwater sections. The cave passage is wide and well-lit with natural light in the entry sections, making it suitable for snorkellers and open-water divers as well as cave-trained divers exploring deeper passages. Freshwater eels, river prawns, and endemic crustaceans inhabit the system. Temperature drops sharply from the warm sea into the cool 22°C freshwater stream — a remarkable halocline experience.