How and where can I see the Data Center for our Netsuite instance?

Do a "View Source" on any logged in page in the NetSuite User Interface. Scroll all the way to the bottom. It will list off the host information. The host name indicates the location.... for example: a220.prod.phx.na3.core.ns.internal "PHX" is the Phoenix datacenter.

Thanks a lot for the info. It seems we are in PHX as well. a207.prod.phx.na15.core.ns.internal

No problem! Our instance used to be in the BOS (Boston / NA Northeast) datacenter, and after the Oracle Cloud Infrastructure (OCI) migration, we were moved to PHX. I think Oracle consolidated a lot of NetSuite accounts to Phoenix as a result of OCI.

It's also on the Company Information page now