I read that the Barclays vault in London is one of the largest...

I read that the Barclays vault in London is one of the largest in Europe. But that's a small part of the bigger picture.

In 2013 the JPM's building in New York which housed the largest vault in the world was bought by Fosun, China's largest conglomerate. No info on whether the Chinese govt. has seats on Fosun's Board. But what would Fosun do with the world's largest vault? Perhaps lease/sell/give it to the Chinese govt in return for govt approval for overseas investment? If the Barclays vault is 1.5k-2kT in gold storage capacity, then the JPM vault is at least 2kT.

Within China:
1. SGE has storage capacity of 1kT.
2. Shortly after the SGE Rmb gold fix launch in 2014, the HK CGE announced that it will be building the largest gold vault in the world in China. The capacity would be > 2kT. Until then, a temporary facility is being used. No info on its storage capacity. No info either on the progress of building that new vault. But it wouldn't take the Chinese too long to complete the project.
3. To account for the state-controlled banks' vaults in China as well: if the official reserves of 1.8kT is used as guidance, then the state banks' capacity would be about 2kT.
4. China is analysed as using its citizens to store gold, which China can confiscate for national purposes. As it also can from SGE and Chinese banks. Hence, no gold may leave China without the govt's approval. Citizens' gold holdings is estimated at 16kT. If even 10% of the total is successfully confiscated, that's 1.6kT.

As an aside, there are reports that the Swiss vaults hidden deep inside the Alps are in high demand by the super rich. Interestingly, these vaults have websites with Chinese language versions.

I think that in the speculation about China having at least 10kT of above ground gold reserves, the underlying assumptions cover much wider concepts to include national strategies rather than just limited to physical storage capacity in vaults outside of China. Cheers. R.