Balator
Galadon Graveyard
Arboria
One north of Udgaard
East of Arkham
Arkham Sewers
I think Underdark can be considered Graveyards, but not sure
Hamsah

As for soloing necs, it depends on what levels.

If you know the right mobs, you can solo most classes to mid 30s.

Low levels - seaport
Get to level 11 - buy the skull from Galadon (give your vampiric touch through an item)
Commoners/dwarves/Plains of Udgaard until early 20s when you get a golem
Dwarves/Plains of Udgaard/Darsylon until you can animate corpses
Once you animate corpses and you get a decent army, sky's the limit.