Borneo (Kalimantan)

Indonesian Borneo covers two-thirds of the world's third-largest island, with vast rainforests and river-based Dayak communities. It harbors over 15,000 plant species, outperforming #2 Sumatra in botanical diversity, and its canopy walkways rise 30% higher than the average Indonesian nature trail, while its orangutan population exceeds that of Sumatra by 20%.