The Main Shrine is where the remains of one of Japan’s most venerated Lords, Tokugawa Ieyasu is enshrined.
A couple of things I look for in a shrine is the elaborate colors and reliefs that are used, which not only represent the prosperity of the people who built it, but also the spiritual quality of the person who was deified in it.
Another thing I look for is the style in which the inner sanctum was designed. The most widely recognized design style is the Gongen-zukuri style where the inner sanctum is interconnected to a series of corridors and hallways in the shape of an “H.” This shows a unifying link between Buddhist and Shintoism dating back all the way to the Heian period(798-1185).
Main entrance to the hall of worship which is called the Kara-mon Gate and Haiden, both national treasures.