Imaginary wonderful place (6)
I believe the answer is:
xanadu
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">imaginary wonderful place</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for xanadu that I've seen before include "Fabulous place" , "Kubla Khan's place (Coleridge)" , "Where Kubla Khan built his pleasure dome" , "'In . . . . . . did Kubla Khan / a stately pleasure-dome decree' (Coleridge)" , "ideal place" .)