Shooting model for Hogwarts castle

Question

In the Harry Potter movies, we see long shots of Hogwarts castle, having tall spires, perched on a steep rocky hill above a lake. Were these shots taken of a real castle actually built in such a setting, or are they all effects shots? If they are of a real castle, what does the real castle look like (just as shot, or embellished)? I know that some shots appear to take things to a bit of an extreme, and could be impossible to engineer, but when you consider Neuschwanstein, how it was designed and where it was built, one could easily imagine that a castle looking very like Hogwarts could actually exist, and in just such a setting as depicted.

I know some exteriors like Harry's flying lesson were actually shot at Alnick Castle, but Alnick is a very different-looking castle situated in very different topography. I'm referring to the long shots which show the castle in its rather spectacular location.

Answer 1

It was a model.

Although some exteriors were shot at Alnick Castle, and some interiors shot at Christ Church Cathedral, the long-shot exteriors were all of a detailed miniature (or, as some people call them, a bigature, due to the size).

This is a picture of the actual model used in all the films:

There is an article here showing the actual size and some more information about it.