Some mountain ranges around magical land (6)
I believe the answer is:
narnia
'magical land' is the definition.
(I've seen this before)
'some mountain ranges around' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'around' says the letters should be written backwards.
'ainran' is hidden within 'mountain ranges'.
'ainran' back-to-front is 'NARNIA'.
(Other definitions for narnia that I've seen before include "C. S. Lewis's imaginary land" , "The Land of Lions, Witches and Wardrobes?" , "Land of the Lion, the Witch and the Wardrobe" , "C.S. Lewis's imaginary country" , "magical land" .)