Fabled city (2,6)
I believe the answer is:
el dorado
'fabled city' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for el dorado that I've seen before include "Golden land imagined by the Spanish explorers of America" , "Imaginary land of riches" , "Fabled place of wealth" , "'Imaginary place of great wealth and opportunity (2,6)'" , "Place of great wealth, from fictitious city on the Amazon" .)