Black Sea
The Black Sea was a sea on Earth. This sea at night was always a stimulating experience for Worf.
In 2370, aboard the USS Enterprise-D, Worf and Deanna Troi went on a date in the holographic program Black Sea at Night. They were walking barefoot together on a beach along this sea listening to balalaika music. (TNG: "All Good Things...")
The Black Sea on a statistical era map