US-East isn't a single building. Per AWS its over 10 datacenters that make up US-East(from a post they had in 2012). You aren't in the same building as their availability zones, you are probably talking about their Direct Connect POPs which is something completely different.

--(updated with links)--

https://aws.amazon.com/message/67457/

https://aws.amazon.com/directconnect/details/