Trottingham and hoofington sure gates to tartarus uhh sure let’s put a dangerous place where Antagonists can go to sure . . . .

Tartarus only appears in the Dark Hour.  
I thought everyone knew that.

Tartarus I mean.

Trottingham and Hoofington are obviously in the Uneighted Kingdom, which is across the Channel from Prance.

Dangit, Splinter!

I accidently my grammar

@Princess♠Molestia
 
Okay, just wondering. Didn’t want to make a fool out of myself. It seems like Equestria filled with pony names of US cities (Las/Los Pegasus, Fillydelphia, Appleloosa, ect.) Trottingham is probably across the ocean in some MLP version of Europe.

My headcanon is that Trottingham is not on mainland Equestria, but rather on their own separate island(whether it are part of Equestria or independent is another thing.) This is because Equestria is based on the US and Canada while the city Trottingham is based on is in the UK.  
As far as I know Hoofington is not based on a real town or city. Since Trixie was lying about stopping the Ursa Major, perhaps she was also lying about a town called Hoofington existing? Either that or the artists forgot it.  
As for Tartarus, the artists forgot it, or maybe it is not on mainland Equestria either.

I imagine it as a gate that located somewhere deep underground. Like the underworld in Greek mythology.

@BG
 
No, I think they are based on places in Britain. Except Tartarus, that’s Hell.

Is Nottingham, Tartarus, and whatever Hoofington is based on in the US?

I kinda agree about Tartarus.
 
Dangerous locations should be listed so you can give them a wide berth.

My guess for Tartarus is because it’s probably another plane of existence, with a portal to it and all that jazz.