The term Vault has many meanings, the architectural meaning is a room with an arched, self-supporting ceiling. That not the point with our vault category. We are talking about the vault at Gringotts, where Harry Potters parents stored their gold and trinkets. Every bank has such a vault, but most of them are not open to the public. Even as a customer you will not see them.
So there are only a few listings for this category. Vaults become accessible after the bank was shut down or moved to another building. Sometimes they are used as museums or for shops or pubs.
And then there are places which were used as vaults during wars, to store the valuables of a whole country. They are more like bunkers, and often do not have those massive safe doors.