https://www.polygon.com/2019/2/10/18219293/fallout-76-vault-63-location-inside-dlc-cut-content

A Fallut 76 player accidentally clipped into and was stuck inside the supposedly inaccessible Vault 63 — a sealed area players believe may be the scene of some upcoming story extension or DLC. After radioing for help from Bethesda Game Studios itself, they managed to get free on their own, but still have the lingering worry of a ban or another sanction.

Redditor McStaken said they got stuck there doing a Rad-Rat horde event. While inside, they snapped and shared these nine pictures (via imgur) of Vault 63’s interior.