Olympic arenas are host to a worldwide spectacle - tonight's opening ceremony in Rio de Janeiro is expected to net worldwide audiences of three billion.
But what happens to the Olympic parks when the Games are over?
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Here are some of the abandoned Olympic venues which were once spectacular.
1. Athens, Greece - 2004
The Games cost Athens a huge amount, £9 billion to be precise. In 2015 some of the former Olympic venues became temporary shelters for migrants. The other areas remain unused, with rubbish piling up.
2. Berlin, Germany - 1936
The Berlin Olympic village has seen some rough times. It was used as barracks by the German army after 1936 and after WWII it was occupied by the Soviet army. They then abandoned it in 1992 and it has since been unrestored.
3. Munich, Germany - 1872
Named the Bahnof Munched Olympiastadion, it housed a train station for easy access to the games. The venue is now a canvas for local street artists - the trains no longer run and the graffiti lines the walls.
The Linnahall was built for the 1980 Moscow Games' sailing events. A brutalist style building, it has heritage protection. The Tallinn Government is hoping to renovate the area by 2018... at the estimated cost of €65 million.