Primrose Hill was a park in London.
In 2010, the Doctor's TARDIS arrived at Primrose Hill so that the Eleventh Doctor and Amy Pond could view London on a clear day. However, it had inadvertently materialised around Stephen, a boy who had run up the hill to evade the Space Leech invasion. (COMIC: Attack of the Space Leeches! [+]Loading...["Attack of the Space Leeches! (comic story)"])