The reason for Atsuta's standing lies in a thing no one is permitted to look at. Kusanagi-no-Tsurugi, the Grass-Cutting Sword, is enshrined here as the shintai, the physical vessel of the deity, and is not displayed to worshippers, to visiting officials, or even to the shrine's own priests. There is no viewing on any anniversary and no photograph; what pilgrims approach is the closed honden behind its fence.
The one near-contemporary account of anyone glimpsing it, recorded in an Edo-period document, describes priests who broke the taboo and were said to have fallen ill, a story that only hardened the prohibition. This restraint is deliberate and respectful rather than secretive for its own sake: in Shinto the object's power is bound up with its concealment, and the imperial regalia in particular are understood to be handled by almost no one across an entire reign. The Kusanagi-kan museum, opened in 2021, satisfies visitors' curiosity about swords by showing the shrine's large collection of other blades, while the regalia sword itself remains, as it has for centuries, unseen.