The Koka-ryu Ninjutsu Yashiki in Shiga Prefecture is a samurai residence that was built about 300 years ago. From the outside it looks like an ordinary one-story house with a thatched roof, but it's actually a complicated, three-story structure that has many tricks and traps hidden away in case of an enemy invasion. The otoshiana, or pitfall, is used to trap enemies. The dondengaeshi is a revolving trapdoor in the wall through which one can instantly disappear. And the nawabashigo, or rope ladder, allows one to go directly from the third floor down to the front entrance on the ground floor.
To get to the Kokaryu Ninjutsu Yashiki, you take the JR Tokaido Line from JR Kyoto Station, transfer to the JR Kusatsu Line at Kusatsu Station, and get off at Konan Station.
The town of Koka (which will become a city in October 2004) is located in Shiga Prefecture, famous as the home of Lake Biwa, Japan's largest lake. It's surrounded by mountains and situated not far from Kyoto, which used to be the nation's capital. Its geography made it an ideal place for ninja to live. Besides the Koka-ryu Ninjutsu Yashiki, the town of Koka also has a Ninja Village, where children can experience a ninja training program.