Secret underground bases are one of the most often scoffed at ideas in all conspiracy theories, but are they really all that unlikely? Read an analysis of the technology and historical precedent that indicates secret underground bases are not only possible, but highly probable.

Tunneling Isn't That Hard
Most people seem to think that tunneling requires brand new, state of the art technology, probably because of all the hullabaloo about digging a tunnel underneath the English Channel. The fact that it took this long to develop a way to dig through mud underneath an exceptionally large body of water isn't that surprising, and it's a whole lot easier to tunnel through dry ground, particularly in areas with a low water table or soil that is for some reason or another particularly stable.
When taken as a whole, tunneling and other underground construction isn't new, or even modern for that matter. For a quick example of ancient tunneling, a "maze" of underground tunnels was unearthed in 2000 near Camlough, Ireland. These tunnels had been laying, unknown to the world and passed off as mere rumors by the experts for as long as 2000 years before being discovered accidentally by a team of water service workers. If tunnels dug shortly after the death of Christ can be deep enough and hidden enough to escape detection for two millennia, the US government should certainly be able to pull it off. (McIntyre, Jacqueline. The Irish Times. Jun 14, 2000)

Tunneling Has Been Done
We might not know much about the tunnel systems underneath our own country, but our government has been less active in keeping secret the tunnels of other countries, particularly those dug by our enemies. A fair amount is known and documented about the tunnels dug in the former USSR and North Vietnam in particular.
Moscow is known as a site of exceptional underground development, and has only recently been actively explored and documented. According to a Russian organization known as the "Diggers of the Underground Planet," Moscow sits atop 6 layers of tunnels, with some areas going as deep as 12 layers. The origins and ages of the tunnels run the gamut from modern sewage tunnels alongside Soviet bomb shelters and nuke-transporting trains to drainage tunnels built in the 18th century, all the way to natural underground rivers. (Ilnitsky, Andrei. Bulletin of the Atomic Scientists. May/June 1997 pp. 11-14)
During the Vietnam war, an extensive system of tunnels sprang up, all dug without sophisticated machinery by the North Vietnamese. These tunnels were dug mostly with picks and shovels, with the dirt removed from them dragged out by hand in buckets. Viet Cong tunnels have been discovered as deep as 60 feet, and it is possible to travel the entire distance from Saigon to near the Cambodian border through them without setting foot in the fresh air above, something like 150 miles of tunnels dug without any of the tools our government has access to today. (

Still Don't Believe?
So tunnels can be dug, over extensive areas, with or without advanced equipment. Tunnels have been dug by other governments for various reasons, as early as the Cold War. Still and yet though, many see secret underground tunnels as impossible, or "too out there" and something that is only believed by a handful of kooks. The Russians did it in the Cold War, and the Viet Cong did it in Vietnam. So why would we not be doing it now, with access to the most high-tech tunnel borers ever created?