I have not seen a world map yet --- but the city is GIGANTIC - there are trains on a rail system that can take you to certain parts of the city its so big.
PvE: There are sewer entrances and things like that. You can enter it to farm for items or to quest. The entrances are usually scattered and etc.
I got to tell you man --- encountering these guys:
http://img88.imageshack.us/img88/3369/hardjg7.jpg --- HARD AS HECK but they give 61 exp so I cant argue lol.
Also:
http://img88.imageshack.us/img88/5891/peoplekf9.jpg
There are ALOT of people playing and surprisingly I have experienced any major lag.
The second reason I like Alternix
This pic if for people age 13+ only please:
http://img337.imageshack.us/img337/2504/buttyt2.jpg