There are about 1300 Asama (浅間) or Sengen Shrines in Japan. Most of these are within sight of Mount Fuji. Where this is not possible, because of distance or some kind of obstruction, a miniature replica, known as a Fujizuka (富士塚), made of stone from the mountain, is usually set up within the shrine grounds. Many Sengen Shrines are in Shizuoka or Yamanashi, but Chiba Prefecture has the greatest number.
The head of all the Asama (or Sengen) Shrines is Fujisan Hongū Sengen Taisha, which is in Fujinomiya in Shizuoka Prefecture. However, if you climb from Yamanashi Prefecture to the top of Mount Fuji, you will be visiting the Shrine in any case. You also will not be in any particular prefecture.
If you climb to the top of Mount Fuji, you will be visiting Fujisan Hongū Sengen Taisha because the whole of the top of the mountain from the Eighth Station upwards is considered to be part of the shrine grounds. In 2013, the shrine was added to the World Heritage list, along with six other Sengen shrines, as part of the Fujisan Cultural Site. It is not exactly clear when Fujisan Hongū Sengen Taisha became a shrine but it was certainly a very long time ago. The shrine tradition claims that it was established over 2,000 years ago!
It is also not clear how the name Asama or Sengen originated. It may be that, originally, worship of mountains was centered on a completely different mountain called Asama. Then, because Mount Fuji was the biggest and most famous mountain in Japan, it began to dominate and attention shifted to Shizuoka and Yamanashi. Also, Mount Fuji has erupted eighteen times in recorded history; it was considered very important to keep the mountain happy in order to pacify the kami of the mountain. In the early Heian Period (around 800), Mount Fuji was given high rank as a member of the royal court and regarded as a great kami (大神). From around this time, worship of volcano kami as providers of water became combined with secret and magical Buddhist training practices.
Shugendō is a Buddhist religion closely linked to the Sengen Shrines. For Shugendō practitioners, enlightenment takes the form of becoming one with the kami of the mountain. Their goal is to understand the true relationship between nature and humanity through enduring an incredibly hard lifestyle on a mountain. For a long time, only Shugendō monks were allowed on the mountain.
From around the ninth century, the rules were loosened and half magical and half religious activities centered around Mount Fuji became popularized. However, women were still forbidden from climbing the mountain.
Featured image: Utagawa Hiroshige (歌川広重) [Public domain], via Wikimedia Commons