Filming on the third Harry Potter film, Prisoner of Azkaban, began on Monday 24 February, and CBBC Newsround couldn't resist taking a peek.

I'd been sent to the gates of Leavesden Studios in Hertfordshire to check out the chaotic, buzzing festival of awesome wizards and magical mayhem.

Well, that was the idea.

But, as you can see from the pix, the first day of filming was a pretty quiet affair from where I was standing.

Mysterious black windows

Loads of cars went in and out, some with mysterious blacked out windows - who was inside?

There were tons of vans and lorries carrying hundreds of planks of wood, strange looking canisters of gas and food for the cast and crew.

But nothing which gave anything away.

If there was any filming happening, it was well away from public view, in one of the huge sound stages which hold loads of the sets.

Eventually I left, after a worried looking security man asked why I had been hanging around the front gate for ages on my own.

So, nothing to report, which, when you think about it, means there are no big problems!