The Derawan Islands in East Kalimantan offer a truly unique and diverse marine experience, ranging From Harmless Jellyfish in an isolated lake to majestic giant manta rays in the open ocean. This archipelago is a hidden gem for marine enthusiasts, presenting an extraordinary spectrum of underwater wonders. The allure of Derawan lies in its ability to cater to various interests, whether it’s swimming From Harmless Jellyfish in a freshwater lake or encountering massive pelagic creatures. Indeed, the transition From Harmless Jellyfish to giant mantas encapsulates the incredible biodiversity found here. A report by the Ministry of Tourism of Indonesia, published on July 2, 2025, highlighted Derawan as a rising star in eco-tourism, particularly for its unique marine attractions.
The most famous and unique attraction From Harmless Jellyfish is undoubtedly Kakaban Island’s Jellyfish Lake. This ancient marine lake, isolated from the open sea for thousands of years, is home to four species of jellyfish that have lost their stinging cells due to the absence of predators. Visitors can safely swim and snorkel among these mesmerizing, pulsating creatures, an experience that feels otherworldly and incredibly peaceful. It’s a rare opportunity to interact directly with these delicate beings without any threat. A group of tourists on June 20, 2025, described their swim in Kakaban Jellyfish Lake as “an absolute highlight, truly magical and serene.”
Beyond Kakaban’s unique lake, the charm of Derawan extends to its vibrant open-sea dive sites, particularly around Sangalaki and Maratua islands. Sangalaki is a renowned sanctuary for giant manta rays. Divers and snorkelers here have frequent opportunities to observe these magnificent creatures gliding gracefully through the water, often gathering at cleaning stations. It’s a breathtaking encounter that showcases the raw power and beauty of the ocean’s giants. Furthermore, Sangalaki is also an important nesting site for green turtles and hawksbill turtles, allowing visitors to witness turtle conservation efforts firsthand.
Maratua Island, another key part of the Derawan archipelago, offers spectacular wall dives and rich coral reefs teeming with reef sharks, barracudas, and diverse schools of fish. Its famous “Goa Haji Mangku” is a stunning cave system that divers can explore. The combination of its unique stingless jellyfish, the awe-inspiring giant mantas, and the overall healthy marine ecosystem truly positions the Derawan Islands as a must-visit destination for anyone seeking a diverse and unforgettable aquatic adventure. The journey From Harmless Jellyfish to giant mantas defines the extraordinary appeal of Derawan.