Dungeons

Sastasha - Level 15, story
The Tam-Tara Deepcroft - Level 16, story
Copperbell Mines - Level 17, story
Halatali - Level 20, optional (though contains mobs required for GC hunting log)
The Thousand Maws of Toto-Rak - Level 24, story
Haukke Manor - Level 28, story
Brayflox's Longstop - Level 32, story
The Sunken Temple of Qarn - Level 35, optional
Cutter's Cry - Level 38, optional
Stone Vigil - Level 41, story
Dzemael Darkhold - Level 44, optional (though required for GC progression)
Aurum Vale - Level 47, optional
Wanderer's Palace - Level 50, optional
Amdapor Keep - Level 50, optional (though required for GC progression, and lots of tomestone grinding!)