Reijo (Sacred Places) (霊場)
A reijo is a place where human souls are said to gather after death. Worshipped by people since ancient times, reijo are visited even today by many ohenro san (pilgrims) as well as many ascetic Buddhist monks.
There are many reijo, including Osore-zan Mountain, Mt. Hiei, and Koya-san Mountain. Many of them have roots in mountain worship, but not all reijo exist on mountains. Some of them are located along the coast, for example Shido-ji Temple (one of Shikoku's eighty-eight sacred places), and others underground, such as Benten Dokutsu (Benten Cave) located in Inagi City, Tokyo.
In addition to places connected to mountain worship, reijo also include sites where historical battles were fought. Furthermore, recently places where many people died in wars have been treated as reijo. For this reason, many reijo where furious battles were fought are also located outside Japan, and groups of pilgrims from Japan visit these reijo every year to hold memorial services.
In Japan, the Saigoku Sanjusankasho (thirty-three temples for pilgrimage in the western region), Bando Sanjusankasho (thirty-three temples for pilgrimage in the Kanto region) and Chichibu Sanjuyonkasho (thirty-four temples for pilgrimage in the Chichibu area) are together called the hundred Kannon Temples (after the Deity of Mercy).
The term "the hundred Kannon" has existed since the Heian Period, although what the term refers to has varied over time
However, nowadays, "the hundred Kannon" generally indicates the hundred temples of Saigoku Sanjusankasho, Bando Sanjusankasho and Chichibu Sanjuyonkasho as described above.