Amnnon Arena?

I know that there is one, but how so I get to it? lol

It was moved when they created the Battle Isles. You can't get there anymore.

There isn't one. It was removed a long, long time ago. All of the PvP content has been shifted to the Battle Isles. The Fort Koga map in the Random Arena/Team Arena cycle is the map that was played in Amnoon Arena.

They dismantled and relocated the Lion's Arch(LA), Droknar, Denravi and The Crag arenas back in January.
They also changed The Tomb of Forgotten Kings to a farming local and moved it's original purpose to Hero's Ascent(HA) in the Battle Isles.
If your attempting to use the strategy guide(or the guild wars map) you would be better off throwing that out and going it alone.
On a simliar note can anyone post the locations of the Factions arenas, I just discovered there was an arena in Shing Jea(big news to me).

That's the only Arena in Cantha. After that you need to get to the Battle Isles via Kaineng Docks