EU+US Best place for challenging wPvP as a 39 twink?

About to reinstall as a buddy finally got his PC going.. going to play endgame with him but since my twinks are useless now I'd still like to have a little fun on them.

As a horde 39, where should I be going for some wPvP? Multiple zones/levels appreciated! Havent played in a while.. thanks in advance

The game has now implimented level scaling in all zones. NPCs and quests are now relevant no matter what level you are (broadly speaking).

However I'd suggest Un'goro Crater - usually a lot of level 40+ toons questing here and it's a nice area to re-live nostalgia.
Ganking someone and them running into the huge dino is always funny.

That's a pretty niche question. I'd say level up 81 more times then join a guild of like-minded droolers with a fetish for ganking questers/world questers.