Apparently, Japanese Nightingale Floors are Ninja-Proof!

What’s a surefire way to keep thieves from even entering your home? Back in the Edo period in Japan, there obviously weren’t electronic alarm systems to keep intruders out.

While they had guards, these guards were no match for sneaky ninjas who could sneak in without being detected. So instead, they created the uguisubari or nightingale floors.

They look like regular floors, but the secret lies beneath the planks.

Nightingale floors look like regular floors, but beneath the floorboards, it has a unique twist. It gets its name from the sound it makes when people step on the planks. The woodworkers and craftsmen who install these floors would place planks of wood on supporting beams.

However, they’d be placed securely enough to hold weight without dislodging, but they’d be left just a little loose. This way, when the planks are stepped on, the clamps securing the beams would rub against the nails to create a chirping noise.

These beams would rub together to create a noise when someone steps on them.

Here’s a closeup of the beams that create the famous chirping sound:

One of the most famous nightingale floors can be found in the Nijo Castle in Tokyo, Japan. Nijo Castle was the main seat of Japan’s power, and as you can imagine many important people would stay there.

Nijo Castle, once the seat of power in Japan, has nightingale floors that tourists can try out.

Naturally, there’s always the threat of theft or assassination, so these nightingale floors served to warn them if an intruder is lurking in the castle. In fact, these floors can even give out a unique sound so guards can pinpoint exactly where the intruder is!

Other nightingale floors can be found in the Chion-in Temple in Higashiyama-Ku, Eikan-do-Zenrin-Ji temple, and the Shingon Buddhist Temple, Daikaku-Ji in Kyoto.

Watch this video to hear the sound of these nightingale floors: