Nightingale floor

These floors were used in the hallways of some temples and palaces, the most famous example being Nijō Castle, in Kyoto, Japan.

An information sign in Nijō castle states that "The singing sound is not actually intentional, stemming rather from the movement of nails against clumps in the floor caused by wear and tear over the years".

Legend has it that the squeaking floors were used as a security device, assuring that no one could sneak through the corridors undetected.

[1] The English name "nightingale" refers to the Japanese bush warbler, or uguisu, which is a common songbird in Japan.

[3] The verb haru becomes nominalized as hari and voiced through rendaku to become bari.