At the first modern Olympics in 1896, events were held in the Bay of Zhea, off Piraeus. The early Olympic events included a 200m obstacle race, in which competitors had to climb over and swim under boats positioned on the course. The distances were rationalised by 1912, the year that Duke Paoa Kahanamoku became swimming's first superstar.
Plenty more followed, including Buster Crabbe, the 400m freestyle champion in 1932, who is best remembered for his roles as Buck Rogers and Flash Gordon. Johnny Weissmuller, who played Tarzan in 12 films, won five Olympic titles (1924-1928), but he is not the benchmark for modern swimmers.