Nightingale floor

Listen to A Nightingale Floor (Japanese鴬張り, uguisubari )? / I is a floor that causes a chirping noise at each step and thereby betrays invaders. The sounds arise upon entering the soil by shifts of pins that secure the planks of the floor.

The sound resembles the sound of Japanese Nightingale (Japan Buschsänger ). This explains the name of the floor. This form of " alarm " can be found for example in the Nijo - jo, in Eikan - dō and Chion-in temple in Kyoto.