The group includes Kim Son (Mountain of Metal), Moc Son (Mountain of Wood), Thuy Son (Mountain of Water), Hoa Son (Mountain of Fire), and Tho Son (Mountain of Earth). Several Buddhist temples have been built into the caves and grottoes, and it's a popular pilgrimage site. The real fun, though, is at the Am Phu cave, where you can make the steep climb up toward the light and a view from the top of the mountain, surrounded by approving sacred images; or head in the opposite direction, physically and spiritually, down to the crude Hieronymous Bosch-esque statues of sinners getting their due in the caverns below, with appropriately eerie lighting. Either way, wear walking or climbing shoes. Open-tour buses will stop here, but you'll be rushed along; any motorbike taxi in Da Nang or Hoi An will be happy to take you and let you set the schedule. Guides are available. Watch out for the rapacious statue-sellers outside.

The Ngũ Hành Sơn (Vietnamese: Ngũ Hành Sơn, Chữ Hán: 五行山; lit. "five elements mountains"), also known in English as the Marble Mountains, are a cluster of five marble and limestone hills located in Ngũ Hành Sơn District, south of Da Nang city in Vietnam. The five mountains are named after the five elements: Kim (metal), Thủy (water), Mộc (wood), Hỏa (fire) and Thổ (earth).

All of the mountains have cave entrances and numerous tunnels, and it is possible to climb to the summit of Mount Thủy. Several Buddhist sanctuaries can also be found within the mountains, making this a tourist destination.

The area is known for stone sculpture making and stone-cutting crafts. Direct rock extraction from the mountains was banned recently. Materials are now being transported from quarries in Quảng Nam Province.

Marble Mountains was officially given the National Special Relic certificate by the Ministry of Culture, Sports and Tourism on January 20, 2019.