Torii translated to mean “where birds dwell”, is symbolic of the entrance to Shinto Shrines, and the doorway to a sacred place. It also means the transition from the physical world to the spiritual world. The kasagi, or top beam of the torii, is often curved, suggesting the image of “wings”, as showing in the above photo of Tacoma’s Point Defiance Pogoda and Japanese Garden. The second beam, or shimagi, appears to be a support beam, located directly under the kasagi, and is slanted inward. A third and final cross beam, the nuki, is separate from the two upper beams, but not too far below them. The hashira are the two supporting pillars which hold up the torii. They are often rounded like poles, but can be square shaped as well. There might also be a small gakuzuka support post that connects the nuki and shimagi at the center.
The significance to me of the spirit behind Shinto is it’s lack of a building structure such as a church, synogagogue, or mosque. The torii and the jinja (where the kami dwell) come closest to the spiritual place of worship of these western structures.
Kami and nature are virtually the same. The way of the kami, or kannagara no michi, we become filled with the energizing spirit of nature, and positive and negative ions. Each kami possess positive and negative energy, good and evil. Musubi is the energy force that connects humans and nature and the world to each other as we strive to unite with our higher spiritual power. You may find more information at the Tsubaki Grand Shrine of North America , at http://www.tsubakishrine.org/.