Ecosystems in Vietnam

This network of tunnels housed an entire village for years, and even had a hall for screening movies.

This cavern was used as a hidden hospital and safe house during the Vietnam War.

This Vietnamese hell cave lets visitors take a walk through a devilish underworld full of demons.

Ha Long Bay's "Cave of Surprises" houses a popular phallic rock formation.

World's largest cave was only discovered in 1991, and now offers tours to the public.