Do enemies and objects respawn?

Question

Although I've played the game for some time now, I still couldn't find out whether certain objects and NPCs respawn or not.

I'm particularly interested in:

• Enemies
• Herbs
• Lootable objects.

While playing I've often encountered some locations where I was sure that I killed some enemies that weren't there anymore after a second visit. On the other hand I've also got the feeling that some enemies respawned although I killed them.

Now do enemies and objects actually respawn or was that just my imagination.

Answer 1

• Enemies respawn if you don't clear an area - if it's a den/camp, and you "complete" it (dull grey on the map), they will no longer respawn
• Herbs respawn all the time
• Lootable objects (chests, crates, etc) do not respawn

Answer 2

If you want to farm monsters just save and load the game, they will be back. After doing this mediating sometimes works too.