On Christmas Day 1936, the day after their wedding anniversary, the young couple Thor and Liv traveled from Norway to Fatu Hiva. Thor was 22 years old, Liv only 20. Thor was to collect land snails and insects on assignment from Professor Kristine Bonnevie at the Zoological Laboratory in Oslo.

On 28 April 1947, a balsa raft with six men and a parrot set sail from Callao in Peru. The goal was to reach Polynesia. The skipper was the 33-year-old Thor Heyerdahl. The Kon-Tiki expedition was the result of a theory he had pondered ever since his stay on the Pacific island of Fatu Hiva.

In 1952, the ethnologist Alfred Metraux showed Thor a photograph of a stone statue located in the Galápagos Islands. It is similar to stone statues in South America and on Easter Island. Heyerdahl contacted the Norwegian archaeologists Arne Skjølsvold and Erik Reed, and in 1953 they traveled to the Galápagos Islands to examine the statue.

In 1955, Thor Heyerdahl set out on a new expedition to Easter Island. He had five archaeologists with him: A. Skjølsvold (Norway), E.N. Ferdon (USA), W. Molloy (USA), C.S. Smith (USA) and G. Figueroa (Chile). On Easter Island there are colossal stone statues - Moai, in the local language.

The first time Thor Heyerdahl was on Easter Island, the expedition team discovered depictions of reed boats with masts and sails. Now he wanted to show that prehistoric civilizations, on both sides of the Atlantic Ocean, may have had contact using reed boats.

In 1977, Heyerdahl led the construction of his largest reed vessel—18 meters long—where the rivers Euphrates and Tigris flow together in the former Mesopotamia. The boat was named Tigris. They started the voyage from the river Shatt al-Arab in Iraq. The Tigris then continued down the Persian Gulf and out into the Arabian Sea.

One autumn day in 1982, Thor Heyerdahl received a letter in the post. The envelope contained a photograph of a hitherto unknown stone statue from the island kingdom of the Maldives in the Indian Ocean. It enticed him to launch an archaeological expedition, to find out more about those who had made the statue in the photograph.

In 1986, Heyerdahl was back on Easter Island. This expedition is best known for his attempt to transport the Moai. According to a legend on the island, the huge stone statues could walk. Heyerdahl solved the big mystery of how the statues could "walk".

In the period 1988–1992, Thor Heyerdahl led archaeological excavations of the pyramid complex "La Raya" in Peru. In the area there were 26 pyramid-like constructions of sun-dried clay, so-called adobe blocks. The archaeologists concluded that the ruined city outside Túcume was built around 1100 AD.