Harry Potter and the Prisoner of Azkaban - Whomping Willow Can Travel?
If you go to the part in the second movie where they crash the car into the whomping willow you can clearly see they are within 100 yards from the castle, but when you watch when Ron gets dragged into the whomping willow by Padfoot they are quite far from the castle and are on somewhat of a hill. I think they could have caught this because it is so obvious.
Actually, What I think happened is after Ron and Harry crashed into..the staff at Hogwarts might have moved the tree using magic to prevent further damage to the tree and to students who venture too close to the now clearly irritated Willow.
this is because, sadly, they changed castles between movies. i personally to this day don't like the castle because, in the books, there is no hike across a bridge just to get to Hagrid's hut