Archaeologists found 1,000 feet of tunnels hiding an entire underground world

Archaeologists uncovered nearly 1,000 feet of ancient salt-mine tunnels near Hallstatt, Austria

Experts believe mining there began about 7,300 years ago; production peaked around 1200 B.C.E., reaching 1.5 tons of salt a day. Finds include varied tools, clothing fragments and wooden bowls. Archaeologists plan to continue searching the mountain for more chambers and studying the artifacts.