2004 Summer Olympics return of the games to the city where they began. Having previously hosted the Summer Olympic Games in 1896, Athens became one of only four cities to have hosted the Summer Games on two separate occasions (together with Paris, London and Los Angeles). A new medal obverse was introduced at these Games, replacing the design by Giuseppe Cassioli that had been used since the 1928 Games. This rectified the long lasting mistake of using a depiction of the Roman Colosseum rather than a Greek venue. The new design features the Panathenaic Stadium. The 2004 Summer Games were hailed as "unforgettable,
Summer Olympic Games federal government; the country's economic crisis; health and safety concerns surrounding the Zika virus and significant pollution in the Guanabara Bay; and a state-sponsored doping scandal involving Russia, which affected the participation of its athletes in the Games. Tokyo, Japan will host the 2020 Summer Olympics, making it the first Asian city to host the Olympic Games twice. Forty-two sports, spanning 55 disciplines, have been part of the Olympic program at one point or another. Twenty-eight sports have comprised the schedule for three of the recent games, 2000, 2004, and 2008 Summer Olympics. Due to the removal of baseball and