Montreal, Quebec. 1976 (Summer)
Calgary, Alberta. 1988 (Winter)
Vancouver, British Columbia. 2010 (Winter)
The 1940 Olympics were held in two cities of Japan. The summer Olympics were held in Tokyo while the winter Olympics were held in Sapporo.
helsinki
Vancouver and Quebec
Sarajevo, Yugoslavia
Calgary Alberta in 1988
The Olympics are in a different city each time they are held. Cities put in 'bids' with the International Olympic Committee in an attempt to get selected by the IOC to hold the Olympic Games. The IOC selects the cities that will hold the Olympics many years in advance. A link below shows all the cities that have hosted the games.
Montreal (1976 summer olympics) Calgary (1988 winter olympics) Vancouver (2010 winter olympics)
Beijing and Hong Kong
There were no Olympics held in 1930, summer or winter.
Sapporo, Japan in 1972 and Innsbruck, Austria in 1976.
Yes, there are Police Olympics. They are called the World Police and Fire Games and are held annually in different cities around the world.
In the modern olympics, countries and cities takes turns hosting the olympics. So it's different from time to time.