Hidden in the hinterlands of the province are several lakes. The most famous are the twin lakes called Balinsasayao and Danao nestled in the mountains of Sibulan. These are now being further developed as tourist attractions. Balinsasayao, with a shore distance of approximately 1,250 meters and the widest part at about 900 meters, is bigger than Danao.
While one can discover a number of waterfalls in Negros Oriental, only few have actually been properly identified and harnessed for their tourism potential. One such cataract is the Casiroro Falls in the interior town of Valencia.
Steam from beneath vast watershed areas has enabled Negros Oriental to be a major producer of geothermal power in the Philippines. These geothermal fields are located in the municipality of Valencia. The Energy Development Corporation of the Philippine National Oil Company (PNOC-EDC) started developing these geothermal fields in the late seventies, which supply the natural pressurized steam to run the state-owned power plants.