The former headquarters of the Ministerium für Staatssicherheit — the East German secret police, known as the Stasi — is preserved in Lichtenberg exactly as it was when citizens occupied it in January 1990. Erich Mielke's office still has his telephone bank and his personal weapons in the display case; the listening equipment, the wig collection, the smell bottles used to catalogue dissidents' scents for the tracker dogs, all remain. It is one of the most chilling museum experiences in Europe.
The building is a Soviet-era complex in Lichtenberg, a short U-Bahn ride from the centre. Allow two hours; the documentation room with individual case files is sobering but important. The museum charges minimal admission and is less visited than it deserves.