Even on a tight schedule, Stasi Museum (Lichtenberg) earns the hours.
Allow 1.5–2 hr.
Standing in the genuine, eerily preserved nerve-centre of GDR surveillance — with the disguised cameras, bugging kit and Mielke's office frozen in time — is chilling and substantive. The catch: it's out in Lichtenberg, fairly text-heavy and dated in presentation, so it's for the genuinely curious, not the casual.