HANOI, VIETNAM—According to a Vietnam Plus report, more than 700 artifacts were discovered in a cave in northeastern Vietnam’s Bac Kan province by a team of researchers from the Institute of Archaeology, the Vietnam Archaeology Association, and the Bac Kan Museum. Team member Trinh Nang Chung estimates that Tham Un Cave was used as a residence for about 4,000 years, beginning some 5,000 to 6,000 years ago by people of the Bac Son Culture, and ending in the late Neolithic period. Many of the artifacts, he explained, are stone tools crafted from river pebbles. The researchers will return to the cave for excavations and additional study. For more on the archaeology of Vietnam, go to "World Roundup: Vietnam."