i did some testing and found that EU server might still be in US -.-
Borrowed from reddit
http://www.reddit.com/r/elderscrollsonline/comments/20elib/the_eu_megaserver_appears_to_be_located_in_the_us/
The "EU" Megaserver seems to be located in the US, specifically in Cockeysville, Maryland on the East Coast. This is not precisely what I would call an "EU server". Hopefully this is just the case for this beta.
I currently get between 150-180ms to this server on a standard DSL connection from Sweden. As a comparison, pings to other European game servers, for example Battlefield 4 or WoW, are usually around 30-50ms with my connection.
My testing method:
Log into the EU Megaserver, log into a char and switch ESO to windowed mode.
Open task manager, click "Resource Monitor" and select the "Network" tab.
Select the checkmark next to "eso.exe" in the upper window.
Walk around in the game and watch the IP adress with most traffic in the "Network Activity" window. This is most likely the server that processes your characters movement, combat and so on.
Enter said IP adress, for example in my case "198.20.200.93", into a geolocation service such as
http://www.iplocation.net /
http://www.ipligence.com/geolocation.
The current ping to the server will also be displayed in the "TCP Connections" section of the Resource Monitor.
EDIT: /u/Dimillian posted a link to an official news entry that explains the situation. In short, ZOS figured that there is no noticable disadvantage to having European players play on the US servers, so they chose to have the EU servers located in the US to be able to quickly react to any problems during the launch period. Incidentally, they seem to be not quite done with setting up the EU datacenter. As soon as the launch period is over and the EU datacenter operational, they will migrate everyone playing on the US-based "EU server" over to the actual European datacenter - without any user intervention needed. I expect a slightly longer maintenance period during this migration.