Heyerdahl went to Easter Island (Rapa Nui) for the mystery that it provided. He had been working in the Pacific for nearly two decades by that point having spent time in the Marquesas and then completing his Kon Tiki experiment- drifting from South America to the Tuamotu archipelago. In the late 50's and early 60's the Pacific seemed like an archeologist's dream- little to no excavations had been done and funding wasn't too hard to get for surveys of the many megalithic structures found in the Pacific. Rapa Nui had an additional appeal as the likely place where Heyerdahl's South American voyagers would have first settled and so it was there that he looked for early evidence to support his theories of a Polynesian-South American connection. His book, Aku-Aku, lays out much of the material support he believed he had found to support this connection during his digs on Rapa Nui in the late 50's.