I believe you can be level 1 to go into PoM. However, good luck getting your CoV faction to past KOS at lvl 1, otherwise you need A) an uber guild to get through ToV B) A CoHer at the PoM zone.. wait.. Don't you need a key for ToV also? Not sure, hehe.
Too long an answer.
Level 1.
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Kaeg, 48 Dr00d(I SUCK MUAHA) Venrh, monk of the 27th shackle and rising quickly Aureus, Undead Bar