Sarugatsuji

The Sarugatsuji (猿が辻) is the northeast corner of the wall of the Kyoto Imperial Palace.

Summary
Under the influence of the Chinese cosmology imported by the Imperial Court in ancient times, the northeast direction (丑寅) became an object of superstition. In any building, the exterior corner facing northeast, called a kimon (鬼門), was believed to provide a means by which evil spirits and bad luck could enter.

In order to prevent such things from entering the Palace grounds, the northeast corner was built in an unusual recessed shape. By avoiding a convex vertex pointing in the direction of the kimon, the wall, and indeed the entire Palace, could be regarded as technically having no "northeast corner". This was long regarded as a reliable apotropaic technique for "sealing" the kimon.

A wooden sculpture of a monkey was placed under the eaves of the Sarugatsuji. This is believed to have been done because the shinshi of Hiei Shrine was said to have appeared in the shape of a monkey.

1863 murder of Anegakōji Kintomo
On the night of July 5, 1863, the senior official was assassinated near the Sarugatsuji in what became known as the. Tanaka Shinbei's sword was found at the scene of the murder, but he denied killing Anegakōji and performed harakiri during his interrogation. The real culprit was never identified. The Sakuheimon incident was famously depicted in the 1969 film Hitokiri.