Safe haven — at first, only what it seems (5)
I believe the answer is:
oasis
'safe haven' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for oasis that I've seen before include "Place of calm in troubled times" , "quiet spot" , "place of refuge" , "Peaceful area away from trouble" , "Area of calm amid hectic surroundings" .)