Built in the beginning of 17th century this castle was official Kyoto residence of Tokugawa Shoguns. Beautiful decorated Nijo-jo represents Mamoyama architecture. With its gardens, it is not so much a fortress as a palatial residence.
The main complex called Ninomaru contains five buildings with 33 rooms and 800 tatami (straw mats). It is almost entirely constructed of hokonki wood (Japanese cypress). The interior are painted thin wood walls and sliding doors made of rice paper. Buildings have no defensive structures, except one, uguisu-bari (nightingale floor). All the floors leading to Shoguns chambers squeak and creak when anyone treads on them. Special cramps under it move up and down creating the bird-like sound that gives the name.