Fake characters posing in front of the real location.
Hogwarts, locally known as Alnwick Castle is the setting for all the outside shots of 8 of the 8 Harry Potter movies. Located in Northumberland, England near the border to Scotland the castle has a near 1000 year history of battles since the Norman invasion. Due to the lack of bloodthirsty battles in modern times the site has received a large influx of movie battles. Especially Quidditch battles fought here on camera. In addition to the Harry Potter scenes the castle has served as a backdrop to Black Adder, Robin Hood, Elizabeth and Dracula franchises.
Outside shot of the real thing
If you re-watch the movies you can catch the outside movie scenes not only during the Quidditch games but also during the flying lessons with wizardry teacher Madame Hooch. That might not be enough for you so you can actually visit the castle grounds and participate in broomstick flying lessons and other courses related to the Harry Potter universe.