Jellyfish lakes are rare natural wonders found in the Philippines and Indonesia, but the most renowned one is on Eil Malk Island in Palau. This stunning saltwater lake is home to up to five million stingless Golden Jellyfish, which migrate daily in a mesmerizing pattern. These jellyfish share a fascinating symbiotic relationship with algae living in their tissues: the jellyfish carry the algae into sunlight for photosynthesis, and in return, the algae provide energy and nutrients to their hosts. Over 12,000 years of isolation, the jellyfish in this ancient lake have evolved into a unique subspecies found nowhere else on Earth.

Snorkeling is the only way to explore this extraordinary lake, as a toxic layer of hydrogen sulfide lies beneath the safe upper waters at a depth of around 15 meters. However, this should not deter adventurers—the top layer is completely safe, and swimming among the pulsating mass of golden jellyfish is an otherworldly and unforgettable experience.