Applejack takes a look around the TARDIS, while Doctor Whooves fiddles with some dials. "So, Doctor Whooves, where ya'll from? Before Ponyville."
"Please, just call me the Doctor. I move around a lot, but these days I live in the capital of an old Empire. It's got a great history. At one point in time, it controlled territory in nearly every zone of the planet!"
Hints are available here.