Can we have our ball back please?

Noticed this while passing HMP Perth this cold and icy morning. 

Football stuck on top of the prison wall about 30 feet  up. Sadly  (there was little else to do today), I checked on Google Maps and, yes, there is a football pitch on the inside of the wall at this point. 

'Just going to get our ball back, sir' as the prisoners formed a human pyramid up the side of the wall.