The 1984 Summer Olympics, officially known as the Games of the XXIII Olympiad, was an international multi-sport event held in Los Angeles, California, United States in 1984. When Tehran, the only other interested city on the international level, declined to bid due to the concurrent Iranian political and social changes, the IOC awarded Los Angeles the Games by default. This was the second occasion Los Angeles hosted the games, the first being in 1932. 

In response to the American-led boycott of the 1980 Summer Olympics in Moscow, 14 Eastern Bloc countries, including the Soviet Union, Cuba and East Germany, boycotted the Games; only Romania elected to attend. For differing reasons, Iran and Libya also boycotted. Although a boycott led by the Soviet Union depleted the field in certain sports, 140 National Olympic Committees took part, which was a record at the time. The USSR announced its intention not to participate on May 8, 1984, citing security concerns and "chauvinistic sentiments and an anti-Soviet hysteria being whipped up in the United States." Boycotting countries organized another large event in June–September 1984, called the Friendship Games; some participating countries from the Olympics sent reserve teams to the Friendship Games, which mostly avoided overlap with the Olympic Games' schedule (the exception was the Equestrian Show Jumping event in Sopot, Poland). Representatives of the organizing countries, the Soviets in particular, underlined it was "not held to replace the Olympics". Elite athletes from the U.S. and USSR would not directly compete again until the 1986 Goodwill Games in Moscow, organized in response to the boycotts.
Where were the olympics held in 1980?
Moscow