Indonesia stands as a magnificent centerpiece on the Pacific Ring of Fire, a region where the Earth’s geological forces are constantly at work. Among its many volcanic wonders, the Ijen Geopark in East Java holds a special place.
Spanning across the administrative borders of Banyuwangi and Bondowoso, this site is not just a destination for hikers; it is a global treasure that serves as a bridge between ancient Earth history and modern sustainable tourism.
In May 2025, this importance was officially cemented when UNESCO recognized Ijen as a member of the Global Geopark Network, highlighting its unique blend of geological, biological, and cultural richness.
The World’s Largest Chemical Laboratory
The main attraction of Ijen is, without a doubt, its mesmerizing turquoise-green crater lake. However, its beauty is deceptive. This lake is actually one of the largest highly acidic reservoirs in the world. The stunning color comes from a high concentration of dissolved metals and sulphuric acid, resulting in a pH level that hovers near zero.
To put this into perspective, the water is as acidic as a car battery. This extreme chemistry is a direct result of the geothermal energy stored beneath the volcano, which constantly releases volcanic gases into the water.
This acidic environment creates a landscape that feels alien and prehistoric. For scientists and researchers, the crater is a living laboratory where they can study how minerals react under extreme heat and pressure.
The constant hiss of sulphur fumes and the pungent odor in the air are reminders that Mount Ijen remains a very active volcanic system. It is this raw, untamed energy that makes the site a critical point of interest for global geological education.
A Sanctuary of Biodiversity and Human Endurance
Despite the harsh and acidic conditions of the crater, the surrounding Ijen Geopark is a thriving ecosystem. The region boasts a wealth of biological diversity, serving as a home to 14 species of flora and 27 species of fauna, including 6 types of mammals that roam its ancient volcanic slopes.
The management of the geopark has integrated these biological sites into a broader theme of "ancient volcano" conservation, ensuring that the development of tourism does not come at the expense of the natural inhabitants.
The human element is equally compelling. For decades, traditional sulphur miners have been the silent guardians of the crater. These miners descend to the crater floor to harvest bright yellow sulphur, carrying loads of up to 80 kilograms back up the steep, rocky walls.
While modern progress has introduced trolleys to assist some of them, the manual nature of the work remains a powerful symbol of human resilience. This cultural heritage is a core pillar of the Ijen Geopark, offering visitors a rare glimpse into a lifestyle that has remained largely unchanged despite the world's rapid modernization.
The Future of Sustainable Tourism
Since achieving its UNESCO Global Geopark status, Ijen has committed to a model of environmentally friendly and educational tourism. This is embodied in the Ijen Geopark Geological Information Centre (PIGGI), which provides comprehensive data on the region’s archaeological and biological history.
By focusing on education, the park ensures that every visitor leaves with a deeper appreciation for the Earth’s heritage rather than just a collection of photos.
Furthermore, the economic potential of the region is now being channeled through sports tourism and international events. Races like the Tour de Banyuwangi Ijen and the Ijen Green Trail Run have become global attractions that support the local economy while promoting a message of conservation.
Strict regulations on climbing and crater access are now in place to mitigate the ecological impact of tourism. This strategic balance ensures that Ijen remains a leading global destination, where the power of nature is preserved for future generations to witness and study.
