What areas of the game feature randomly generated terrain?

Back in Diablo II, the second you stepped foot outside the Rogue's Encampment, you were in the randomly generated marshes of the Blood Moor.

But my experience in Diablo III has been different - New Tristram, and indeed, the areas surrounding new Tristram seem to be identical for every character I start.

Which areas are randomly generated? Can I tell if I'm in a randomly generated area or not?

Solution 1:

The overworld is entirely hand crafted. Note however: The enemies in those areas are grouped into a pool, from which a set of enemies is randomly generated when you walk around in the area. Also, there are random elements and events (or little side-quests) that can appear in the overworld.

Dungeons are randomly generated. Aside from hallways and connecting walkways, which seem to be completely randomly generated, there are certain important aspects of a dungeon which remain the same (such as the part in Act 1 where you recruit your first follower), but even those are still arranged randomly throughout the dungeon.