Wetting Trap Chair

Rosenborg Castle is the home to many trappings of the Danish monarchy, including the crown jewels and the thrones of the king and queen. It is also home to a less regal chair, one that displays an unexpected love of practical jokes.

Located in the Regalia Room (just off of the Knight's Hall), the chair contains a bellows and pipe mechanism that makes it sound like the sitter is breaking wind. Two metal bars then extend out from under the armrests, locking the sitter in place. 

It's at that point that the water starts to flow. Starting from a tank built into the chair's backrest, water runs into a container that makes it sound like the sitter is peeing. Another pipe takes water to valves built into the armrests, which spurt the water onto the sitter's pants. Finally, pipes carry water under the seat and out the front of the chair.

There is a history of such chairs at court in various European countries, though it's unclear if the chairs were used solely as entertainment or if they were also used to purposely embarrass or frighten.