This tunnel is not very spacious, it is a bit short inside, but it is very bright after finishing.
Really informative guide (his name was Cung). Watch out for his surprise quiz. Luckily we managed to escape without any mosquito bites. I am 5ft 4 so thought that I would have to crawl using my hands and knees but I was able to go through the tunnels by squatting down.
We came here with Vietnam Adventure Tour and our tour guide Uncle Cung was both funny and informative. We saw many different traps and the activities the Vietnamese did in the tunnels. When going into the tunnels we had a choice of going 20, 40, 60, 80, 100 or 140 meters. There was also a souvenir shop but it was quite expensive (can get the same things much cheaper in Ho Chi Minh City). There was a bigger tunnel entrance but I didn't have a picture.