Gilgo Beach was a coastal region on Earth where Benjamin Sisko met his future wife, Jennifer in 2354.
In 2369, the Prophets recreated Gilgo Beach to help Commander Sisko explain to them the concept of linear time. (DS9: "Emissary")
The beach scenes were filmed at Leo Carrillo State Beach in Malibu, Los Angeles County.
Gilgo Beach is an actual beach that is located in Babylon, Long Island, New York
and, interestingly, Babylon, Long Island, adjoins the town of Bayshore which sounds a little like Bajor.