Japanese castle walls were constructed to encompass castles and towns. This was done to protect the territory and lives of the samurai class.

Originally, castles were mainly constructed on mountaintops to offer protection to the area. However, as their purpose changed from serving as a defense to becoming a symbol of status and power where public affairs were managed, they started being constructed on flatland areas also.

During times of intense warfare, castles were used as guard, and control towers were used to keep a very close eye on the war situation. When the country entered more peaceful times, however, they mainly fulfilled a symbolic role. The feudal lords used to live in a separated palace inside the castle walls.

It is said that over twenty thousand castles have been constructed in all of Japan. But due to disasters such as wars and fires, as well as the impact from the government's castle demolition policy, there are only twelve castles that remain as they were at the time of their construction. Some of them have been designated as World Heritage Sites and National Treasures.

Himeji Castle is located in Hyogo Prefecture and it is one of the most famous castles in Japan. It's also known as Shirasagi-jo which literally translates to White Heron Castle, due to its beautiful shape resembling a white heron spreading its wings. In its 400 years of history, Himeji Castle has remained surprisingly intact despite any wars that have occurred.

Matsumoto Castle is located in Nagano Prefecture. The general image of a castle tower, which is symbolic of any Japanese castle, is having white walls, but Matsumoto Castle is known for its characteristic black walls with few white areas.

Inuyama Castle in Aichi Prefecture is a strong castle, protected by the cliffs behind it. It was built in 1537 and can look back on a history of over 500 years.