Most definitely. Assuming they are related in some way to what we need then it shouldn't be a problem. I've gathered dog tallow from werewolves for example.

[ hmm. ciri raises her hand, settling it against her chin and pondering thoughtfully. ]

It sounds rather like our intersections. They are places where the power needed to harness magic is strongest and most accessible but we have places like what you speak of as well. Old places like the temple where I studied or the garden dedicated to Freya on Hindarsfjall.