The Hidden Valley mine is an open pit gold and silver mine, situated in the Morobe province in Papua New Guinea, some 210km northwest of Port Moresby and approximately 90km south-southwest from Lae, the capital of the province. The mine is located at elevations between 2 800m and 1 700m above sea level within steep mountainous and forested terrain that experiences approximately 3m of rainfall per year. The major gold and silver deposits of Hidden Valley are located in the Morobe Granodiorite of the Wau Graben. Crushed ore is conveyed from the Hidden Valley pit via a 3.8km long overland pipe conveyor and is treated at the Hidden Valley processing plant, which uses a two stage crushing circuit followed by a SAG mill, gravity, CCD/Merril Crowe circuit for silver and carbon-in-leach circuit for the gold.
