The richest deposit of tin minerals in Southeast Asia is a world-valued geological heritage. This assessment is based on mineral parameter. The discovery of the richest deposit was carried out by Broken Hill Proprietary Ltd. (BHP) – a world giant mining company originating from Australia, in 1976. This deposit was not discovered by the Dutch who had carried out exploration and mining at that location until 1942. This deposit was buried 70m in below ground level and identified by BHP through ground magnetic instrument and the deposit was trapped in a volcanic ash (tuffaceous) unit whose local name is called as Nam Salu (Norman, 2006).
This deposit has been mined until 1993 leaving openings with dimensions of 293m in length, 197m in width and in 60m. This heritage can be found in the Nam Salu Open Pit Geosite, Kelapa Kampit.