At the bottom of Wales where the border meets England, there is a large forest - UK large, not Germany large - named Forest of Dean. Nearly in the middle of it there is a small area, Puzzlewood, which preserves the ancient times.
It is a small, maze-like area, where it's pretty easy to get lost. The also made it very child-friendly, so it's a perfect time out with family. They also shot numerous movies and series here, including a Doctor Who episode with Weeping Angels.
J. R. R. Tolkien was a regular visitor here; some say that this was the birthplace and the inspiration for Fangorn of Middle Earth.