Thor Heyerdahl's raft (3,4)
I believe the answer is:
kon tiki
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">thor heyerdahl's raft</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for kon tiki that I've seen before include "Thor Heyderdahl's raft" , "Thor Heyerdahl craft" , "Thor Heyerdahl's craft" , "Thor Heyerdahl's boat, named after an Inca god" , "Famous raft" .)