Home of the world's tallest building (5)
I believe the answer is:
dubai
'home of the world's tallest building' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dubai that I've seen before include "Middle East destination" , "Gulf sheikhdom" , "Gulf emirate and port city" , "Arab city" , "Gulf city/state" .)