This is weird, I am sure that I posted a reply to this thread yesterday? Where did my post go?
Anyway, I'll just post it once again:
Get LDoN groups (if you have the Lost Dungeons of Norrath expansion), they provide decent exp and loot (plat as well as augments). If you want to solo, try one of the following:
Oasis of Marr: The orc camps and/or undead near the southern zone line
South Karana: Aviaks at the birdhouse (beware of roaming gnolls though)
The Overthere: southern region near the PoK book; cockatrices drop good plat for your level
Those are the places where my Beastlord grew up... *tear*
(And to answer your question, OT is The Overthere and can be reached by a book in the Plane of Knowledge)