Go to Jail, do not pass Go

Saw this in part of the Torres de Serrano (The main gate of the old city wall built over 1000 years ago), wondered what prisoners got put in here?

[D. Marie Williams More]

I like the shape of the shadows on the step

[Phil Bacon]

@dmariewms Thank you!

[Jim Jones]

Very neat, so did you go in?

[Phil Bacon]

@indianabluejay No - I had a 'get of jail free' card!