The Carolingian Empire did not border any body of water to the northeast.

Here's why:

* Location: The Carolingian Empire was located in what is now modern-day France, Germany, Belgium, Netherlands, Switzerland, and parts of Italy.

* Northeastern Border: To the northeast, the empire bordered the Baltic Sea (which was not a well-defined sea during the Carolingian era), and the lands of the Slavic tribes.

Let me know if you have other questions about the Carolingian Empire!