Some little islands on a..I guess it's a loch. I tried finding the screencap for this but I couldn't, these islands are in the third movie! For a split second before the train scene, you actually see the train traveling through the Highlands and you can see these exact little islands being rained on. I would never have thought to look at those islands and see HP!
Glennfinnen Viaduct in the Glenfinnen area. This is the viaduct that the Hogwarts Express travels on, mostly seen in The Chamber of Secrets. Sorry that you can barely see it. You can just make out the viaduct, starting from the right. You can see the viaduct again in Prisoner of Azkaban.
I'm heading to Burbank in two hours to go to the taping of the Jay Leno Show. Hugh Laurie *swoon*