This location of Escape Haarlem is the room De Meesterkraker, housed in an actual cell of the monumental Koepelgevangenis (Koepelplein 1). You squeeze into the cell of the Netherlands' most famous safe-cracker and must crack his safe via a chain of puzzles. What's special is that the room is completely unstaffed: you click a link, the door unlocks and instructions are inside; staff are only reachable by phone for hints. Reviewers find the puzzles 'not difficult but they keep you busy' and especially praise the authentic location, low threshold and affordable private booking (approx. €95 per group, 2-4 people). Criticism concerns the limited puzzle depth and the cold, inhospitable feel ('no staff accompaniment, that takes getting used to').