Cancun's peninsula (7)
I believe the answer is:
yucatan
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cancun's peninsula</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for yucatan that I've seen before include "Mexican peninsula where Mayas lived" , "N. Mexican peninsula" , "part of Mexico" , "Alcoholic drink" , "Mayan area of Mexico" .)