Storage

[Calvin68]

Are there safe places other than inventory to store items such as alchemy ingredients?

[Elendil / Redshift]

Yes.

Most containers reset after you've been away for more than a week (in game time), just like any space on the ground. However there are "permanent" containers, which never reset. They are not indicated in any special way but there is a method to discover them. Any container (usually a shelf) in which you find a quest item is permanent.

For example there is one in the dungeon near Matras, with the skull in it and a plaque beside on the wall. I don't remember any more off the top of my head but maybe others will chime in.

[Prickett]

You’ll find one shortly after completing the game on the good ending

[Qrak95]

in addition Thor Hammer is a safe place to store unnecessary things, I don't remember exactly where it is but somehow a few locations to the left of the city.