Does Himeji Castle in Japan have a tunnel that with the withdrawal of one stone can collapse?

Question:

I was on a tour within Himeji Castle once and was told about a tunnel that would collapse if a certain rock was removed. I cannot find any information online about this tunnel, however, only a haunted one. Does anyone know if this information is true? I am writing a speech and would love to include this information about Himeji Castle. I would appreciate any sources supporting this knowledge.

Answer:

There are many gates with traps in Himeji castle
You must be talking about "にの門 / Ni no Mon" gate. or possibly "るの門 / Ru no Mon"

"にの門 / Ni no Mon" gate　is a entrance through the basement level. It's tunnel-like root.
The wooden ceiling panel could be easily removed. Once it removed, any enemies entering thorough this root would be exposed to arrows, stones, and gun-fires from upper level.
http://www.tabisuma.jp/user/obaq/knowled…
http://castle.jpn.org/harima/himeji/7.ht…

"るの門 / Ru no Mon" is also a entrance through the basement level.
This gate was intended to be easily blocked with soil. No pile of sand and soil are around today, but it should be ready in the war time. I'm not sure if it could be collapse only one rock was removed, but I guess there should be something. Also the exit point of the tunnel (castle side) is locate under the stone drop and crenel. Enemies would be also exposed to stone drops, arrows, and gunshots.
http://castle.jpn.org/harima/himeji/18.h…

There were many traps in castles in feudal period.