Wherever you stick this decal, it’ll look like you have a nice view of Hogwarts off in the distance. (Unless of course you’re a muggle and then you will see an empty lot.)
It comes in many sizes, the largest of which is 5 feet across. I think to really sell the illusion, you gotta go big or go home. There are some mixed reviews on Amazon about its ability to remain adhered, but 40% rated it 5 stars.