Mountain range contains popular places to go (7)
I believe the answer is:
urinals
'places to go' is the definition.
(places to urinate or 'go')
'mountain range contains popular' is the wordplay.
'mountain range' becomes 'urals' (Russian mountain range).
'contains' indicates putting letters inside.
'popular' becomes 'in' ('in' can mean trendy).
'urals' placed around 'in' is 'URINALS'.
(Other definitions for urinals that I've seen before include "They're taking the piss" , "Plumbing fixtures in the gents" , "Plumbing fixtures for men only" .)