This forest has a dark recent history, as it was here that heavy fighting continued for a period of 15 years between American soldiers and Viet Cong. The latter established an impregnable bastion here that withstood all attacks, despite the obstinacy of the enemy. They planted a dense patchwork of trees and dug an underground network that prevented their movements from being seen - these shelters are now open to visitors. Signs of the conflict are still visible in the form of water holes created by the impact of American bombs.