The tunnel system had three levels. The top level was 3 to 4 meters underground. The second level was 6 meters underground. It served as shelter for children, the elderly, and injured soldiers.
The bottom level, 8 to 10 meters underground, housed hospitals and other accommodations.
The American military attempted to collapse the tunnels by bombing them with B-52 bombers, but failed.
All the tunnels were approximately 200 km long. Admission with a guided tour for tourists costs approximately $19 to $30 per person.
There is also a firing range on the site where you can fire live weapons (M-16, AK-47, etc.) for a fee.