The structural beauty and the sense of history pervading Japanese castles can also be appreciated at an ancient temple or shrine. But the admiration we feel for castles is different from that we feel for an old religious building. Why?
First of all, people visit a castle to enjoy a feeling for the past. The ornate architecture, best seen in the main tower, fosters this feeling, of course, but the forlorn atmosphere does so even more. Matsuo Basho (1644-1694) expressed that feeling well in thishaikupoem:

For the warlords of long ago, castles were a place of glory or failure, and each castle tells its own story, sometimes a tragedy of utter disaster. If you visit one, the atmosphere from that distant age will surely strike you, too.
Another reason Japanese people like to visit castles is to get a feeling for the knowledge and techniques of those who lived long ago. For example, the small holes in the castle wall were made to shoot a musket or jab a spear, and the labyrinth of gates and passageways made sure that an enemy could not penetrate in a straight line to the inner part of the castle. Everything, even the location of the trees, was planned for defense.
If an enemy made it as far as a small turret or the main tower, other dangers awaited, like stones dropped from chutes above. Devices such as these bring to life the warlords of medieval and pre-modern times, and the artisans who made their castles.
But perhaps the main reason why castles have a special place in the hearts of the Japanese is the fact that they are a symbol for the people living nearby. This is obvious when we consider the fact that, after aerial bombardments reduced many castles to ashes in the last days of World War II in 1945, the local people pushed for their reconstruction, or at least the rebuilding of the main tower.And even if the main tower or other buildings no longer exist, and only a moat and stone walls remain, the ancient site offers a sense of tranquility for all who visit there.