Goa Raja Hot Spring Sumbawa

Goa Raja Hot Spring is located near Sumbawa Besar on the island of Sumbawa, Indonesia, in the volcanic arc east of Lombok where geothermal activity associated with the Sunda-Banda volcanic chain creates bicarbonate thermal springs in a landscape of tropical forest and volcanic hills relatively untouched by mass tourism. The bicarbonate mineral composition of these springs carries properties valued for skin nourishment, digestive wellness, and the calming alkaline effects of bicarbonate-rich thermal immersion in the Sumbawa natural environment, offering a therapeutic bathing experience away from the developed tourist circuits of Bali and Lombok. Sumbawa's cultural identity—shaped by the Sumbawa Sultanate tradition and the catastrophic 1815 eruption of Mount Tambora that killed tens of thousands and caused the global 'Year Without a Summer'—gives these geothermal springs a geological and historical context of extraordinary scale on this Indonesian island.