Fuji is an active volcano that Japanese religious tradition once let only men climb, and both facts shaped who could approach it and how.
Still capable of erupting
Fuji's last confirmed eruption, the Hoei eruption of 1707 to 1708, threw ash as far as Edo, modern Tokyo, more than 100 kilometres away, and formed the secondary peak visible on its southeastern flank. It has not erupted since, but volcanologists classify it as active, and contingency planning for a future eruption is a standing concern for the densely populated region around it.
Climbing as devotion, and who was barred
Pilgrim confraternities called Fujiko organised structured ascents from the Edo period onward, treating the climb itself as a religious practice culminating in prayer at the summit's Sengen shrines, dedicated to the goddess Konohanasakuya-hime. Women were formally barred from climbing above certain stations, on grounds tied to ideas about ritual impurity, a restriction that persisted until it was lifted following the Meiji Restoration in the 1870s, after which women climbers were recorded reaching the summit for the first time.
A mountain kept scenic rather than pristine
When Fuji was proposed for World Heritage status as a natural site, UNESCO's advisory body rejected the nomination over litter, development and erosion from mass tourism, which is part of why the successful listing that followed recognised it for its cultural and artistic associations instead.