It's not Five Hundred Acre Wood, but it is Ashdown Forest, so it'd be niggling to say no. It's TQ474301. The clump of trees is quite distinctive, and is called Kingstanding Clump on Pillow Mound, which may be an ancient earthwork. It certainly looks like it could be the site of the heffalump chase, where they go round in circles.
Gill's Lap is nearby, but that's not the view, which is across Old Mill towards the back of The Warren.
The ice cream van in the Caption It thread is taken facing the other way in the car park