General
Kringloop (Thrift Store) List Leiden
Scrap, shop in Rotterdam to buy, well, scrap
Labs and makerspaces
The Humanities Hub at the Leiden University Centre for Digital Humanities has an AI lab, but perhaps even more interesting a small makerspace (3d scanner, 3d printer, camera based scanning).
Digital Art Lab in Zoetermeer has a variety of tools and equipment, open Fridays 13-18.
Space Leiden (hacker/makerspace) (only open on thursday evenings)