A short walk around the former Humboldt Hospital grounds leads to a visit inside its operating bunker from 1941. The tour lasts approximately 70 minutes. Sturdy, closed shoes are required. The bunker is accessible without steps, but there is no seating during the tour and no visitor toilets on site. Tickets must be obtained through the organiser's online shop, which is the only place offering them.

Details can change — check the event’s website before you go.