The MKAD (ring road) was opened in 1961. It had four lanes running  along the city borders. The MKAD marked the administrative boundaries of the city of Moscow until the 1980s when outlying suburbs beyond the ring road began to be incorporated. In 1980, it hosted the Summer Olympic Games, which were boycotted by the United States and several other Western countries due to the Soviet Union's involvement in Afghanistan in late 1979. In 1991 Moscow was the scene of a coup attempt by conservative communists opposed to the liberal reforms of Mikhail Gorbachev.