Gunung Reng is one of the tourism destination located at Batu Melintang subdistrict, Jell, in the state of Kelantan, Malaysia. The location exactly between latitude 5° 42' 00" N to 5° 44' 40" N and the longitude extends between 101° 43' 40" E to 101° 46' 02" E. It has beautiful geological landscape with different geomorphological processes. Gunung Reng has its own potential specifically in speleotourism sector. Thus, a study has been conducted with detailed study of karst geomorphology in the study area and update geological map of Gunung Reng area at scale of 1: 25 000. Mapping, identification, petrography analysis and description have been conducted to establish new inventory of speleotourism site within the district. The study has been done in order to conserved, exposed, and develop Gunung Reng as natural geological attractions also supporting the mogote hill in contributing benefits to the public and the state of Kelantan.