Ticket booths

This one was pretty straight forward, simply one of the ticket booths where spectators can buy tickets to enter the shows. Actually, there's no one inside the booths, someone could believe that the voice they hear from the inside is a recording, but it's the skull on the top the one who is talking.
In a hypothetical game, these things would grant the player access to new areas of the map, after paying the price for the tickets, and could also be vendors of some sort or checkpoints to save the game data.

The incredible Philipp Bormann even made a 3d model based off this concept, which you can see here:
https://www.artstation.com/artwork/LRkeA0