Originally established in 1583 as a small prayer hall by samurai lord Maeda Toshiie, the Myōryū-ji temple was built in 1643, by his son Toshitsune. Hoping to prevent the Tokugawa shogunate from laying him off, Toshitsune married Tokugawa's daughter and purposefully played the fool while he founded a temple complex where his samurai warriors could live and keep possible enemies under close surveillance. 

Designed as a secret fortress, the temple contains a variety of tricks and gimmicks, such as hidden stairs and rooms, pit traps, underground tunnels, and a watchtower. Because the government at the time prohibited construction of buildings more than three stories high, Toshitsune designed the temple so that it would appear to be two stories high on the outside—but is actually has four stories on the inside. There are 23 rooms and 29 staircases, as well as two hidden mezzanines. 

The watchtower, for example, can be accessed through a door hidden in the middle of a secret staircase disguised as a closet. One of the staircases has a hidden trap pit that leads down to the servants' room, so that an unwary intruder could be attacked by a guard stationed below.

Another possible gimmick is the well, located at the center of the building. It's 80 feet deep, but there's—supposedly, though this is unconfirmed—a tunnel that branches off of it, about 12 feet above water's surface, that leads to nearby Kanazawa Castle. But no one has ever attempted to use the tunnel and no known historical texts mention its existence.

These secrets and quirks have led the temple to be known as the Ninja Temple, even though (to the best of our knowledge) it has never been associated with covert agents known as ninjas. Due to its architectural complexities and current decrepit state, visitors need to book a group tour in advance and be accompanied by a guide.