In Japan, it is quite common to see a structure with two vertical posts and two horizontal lintels crossed above the vertical posts. They are mostly made of stone and wood, two traditional materials in building a structure but lately, copper, concrete, and stainless steel are also in use for similar purpose. Majority of these structures found in Japan are painted in red but it's not limited to just this warm color. They may as well be painted with earth colors such as grey, light brown, and light green or just left to the color of its original material (unpainted). What is this structure and what does it represent?
The structure is called torii, a traditional Japanese gate which can be found at entrances to all Shinto shrines and since torii is an important structure for a Shinto shrine, its size can be colossal. Torii gate can sometimes be found built inside the shrines compound too, marking an entrance to another sacred area. Torii symbolizes a change between two different environments, from profane to sacred ground inside a temple. Torii is a symbol of dedication to the Kami gods (Kami no michi) which Shinto devotees worship. To put it simpler, torii is the symbol of Shinto that put a line between the finite world and the infinite world of the gods.
Its name originated from the Chinese words "shin tao" which means "The Way of the Gods" and it has been in existence since 500BC. Shinto faith is indigenous to Japanese people that mixes nature worship, fertility cults, and shamanism. Life energy exists in natural phenomena is worshipped as Kami. Amaterasu, the sun goddess, is the most prominent Kami as she is the offspring of the creator Izanagi (male) and Izanami (female). Meanwhile, four elements of worship are purification, offering, prayer, and special feast. In Shintoism, divine nature in every human being is hidden until it is purified through these four elements of worshipping Kami gods. In fact, Shinto believers consider natural surroundings like mountains, springs, rocks, etc. as sacred objects. More on Shinto from Japan Guide.
However, torii is not only unique to Japanese Shinto. There are some other parts of the world where similar structures (although different naming) stand as sacred object to believers of other faiths. For instance, a torana or vandanamalikas can be found at some Hindu and Buddhist holy structures in India; hongsalmun in Korea is an entrance gate to most Confucian sacred sites; and pailou is also a type of gate closely related to torii for Buddhist temples in China. Whatever the names they give and the slight different designs of the horizontal and vertical assemblies of the gate, it serves one common purpose, which is to tell people "sacred ground beyond this line".
In Japan, torii gates are built in several different designs or styles under two major families, the shinmei and the myojin. What made them distinct and the simplest way to differentiate between the two families is by looking at the shape of the horizontal lintels and the upright supports. Shinmei toriis contain only straight parts in their architectures. On the other hand, myojin toriis can have both straight and curved parts on them. Most of the torii gates I came across will have a squarish wooden panel (like photo frame) in between the horizontal lintels and contain some writings on them, most probably a say of prayer or maybe just a sign like "Enter this way" kind of thing.
Speaking of torii and its significance to Shinto beliefs, I was amazed by the reality where a simple structure like this gives a spiritual meaning to the Japanese people or anyone who follows Shinto. The most famous torii in Japan is none other than the one sitting just before Miyajima Island. Also known as the 'floating torii', this huge, red, wooden and concrete structure is the main gateway to the sacred Miyajima Shrine.
This torii has become the main tourist attraction in Miyajima since the island opened its door to foreigners many years ago. Previously, the island was only meant for the locals of Miyajima as they tried to maintain the sanctity of the shrine. Another floating torii I managed to visit is the one sitting on Lake Ashi. With the sacred elements of the torii and the massive Fuji mountain in the background, it makes one great outdoor photo if the weather is right. I was quite unfortunate here, though.
The other shrine that is really about torii is the one and only Fushimi Inari Taisha. Dedicated to the kami named Inari, Fushimi Inari shrine contains more than 10,000 torii gates of various sizes.
Most of the torii gates here are lined up to make tunnels of toriis and each torii in those tunnels has been inscribed with the company name or individual who donate for the building of the respective torii. This is done as a gratitude and appreciation to the Inari god for the company's success. More on Fushimi Inari Taisha from Wiki.
To get an experience walking under a torii gate, make your way to Japan and get a feel of the ancient Shinto with its red, shiny symbol - the torii.