This is a list of host cities of the Olympic Games, both summer and winter, since the modern Olympics began in 1896. Since then, summer and winter games have usually celebrated a four-year period known as an Olympiad; summer and winter games normally held in staggered even years. There have been 28 Summer Olympic Games held in 23 cities, and 23 Winter Olympic Games held in 20 cities. In addition, three summer and two winter editions of the games were scheduled to take place but later cancelled due to war: Berlin (summer) in 1916; Tokyo–Helsinki (summer) and Sapporo–Garmisch-Partenkirchen (winter) in 1940; and London (summer) and Cortina (winter) in 1944. The 1906 Intercalated Olympics were officially sanctioned and held in Athens. However, in 1949, the International Olympic Committee (IOC) decided to unrecognize the 1906 Games. The 2020 Summer Olympics in Tokyo were postponed for the first time in the Olympics history to summer 2021 due to the COVID-19 pandemic with the 2022 Winter Olympics being held roughly six months later in Beijing.