Thor Heyerdahl's raft (3,4)
I believe the answer is:
kon tiki
'thor heyerdahl's raft' is the definition.
(I've seen this before)
This is all the clue.
(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" .)