It's a place called Bolsover Castle, a few minutes away from where I live. And on the map it's in Derbyshire, England. The castle is open to the public and it is in the care of English Heritage that is maintaining a lot of old places like this. I've got loads of piccies of it since a couple of years back, but this is the best one :)

"Keep smiling, it makes people wonder what you're up to."