Burnham Beeches is just a few miles away from where the rellies live. This forest of ancient beeches is quite impressive. These trees are *so* big...and *so* old. You can easily imagine Robin Hood and his merry men romping through them.
Wikipedia has a nice little write-up on the place, including a list of films shot there: http://en.wikipedia.org/wiki/Burnham_Beeches