Ceremony of keys ??
The oldest ritual of its kind, the Ceremony of Keys occurs nightly at the Tower of London and tickets to the event are typically sold out for a year in advance.
Every evening at 9:52 pm, guards exchange ceremonial words while in Tudor and lock the towers. The keys to the Tower of London are escorted back to the Queen’s residence by the Escort to the Keys.
This ceremony has been held nightly since at least the 14th century, although some think it originated in the Middle Ages and has only been delayed once during the Second World War.