In the DCAU (the common universe of the Bruce Timm DC cartoons), the go-to fictional foreign country has been Kasnia. It was Kasnia that hired John Corben (aka Metallo) in the pilot episode of Superman: The Animated Series. Kasnia was a big player in the pilot of Batman Beyond. The country also showed up in Batman: Mystery of the Batwoman and in several Justice League episodes.
One such episode, "The Great Brain Robbery," aired this past weekend, wherein the Legion of Doom hijacked a trainload of Euros being transported into Kasnia. Once the Justice League gets word of the heist, Mr. Terrific dispatches several Leaguers to a specific set of coordinates, which he types onscreen:
45* 9' 8" N
19* 5_' 13" E
It's not completely legible (Mr. Terrific's head covers one digit), but it's close enough. And thanks to Mapquest, we can easily determine its precise location. It's just a few miles outside of Novi Sad, the second-largest city in Serbia-Montenegro. In other words, it's a spot in the Balkans, precisely where it's always been suggested that Kasnia lies.
So kudos to the JLU team for the attention paid to even a subtle detail like this.