Inside a Cu chi tunnel made by the Viet Cong. Amazing really. 3 levels of these underground tunnels complete with hospital area, dining area, meeting areas, wash areas, cooking areas and not forgetting the important strategy areas. I managed to crawl through one 60metres of the way then cheated and took a short cut out. I don't know how they managed to stay there for so long and not get claustrophobic.

Oh, and there were a couple of bats to welcome us in too