How can I know in what region are my sync vaults (default is automatic)

I’d like to have the fastest sync possible and appreciate the possibility to choose region.
My sync vault were created months ago and I would like to know in what region they are located.
Then I would re-init the sync vault if they are not in my region (Europe).
But if they are in Europe already, it would be useless to recreate the remote sync vault (I’d loose history + extra work)

If your remote vault was created before the introduction of the new servers, it will be in North America. To check: