In 1965 and 1967, two groups of Apollo astronauts traveled to Iceland to study geology. Among the astronauts in the 1967 group were Neil Armstrong and Bill Anders. Bill was on the crew of Apollo 8, the first flight to and around the Moon. Neil was the first man to walk on the Moon.
Learn more:
– Geology training of Apollo astronauts in Iceland
– 2015 re-visit of Apollo astronauts to Iceland