During the 20th century, the city hosted various fairs and conferences, including the Solvay Conference on Physics and on Chemistry, and three world fairs: the Brussels International Exposition of 1910, the Brussels International Exposition of 1935 and the 1958 Brussels World's Fair (Expo '58). During World War I, Brussels was an occupied city, but German troops did not cause much damage. During World War II, it was again occupied by German forces, and spared major damage, before it was liberated by the British Guards Armoured Division on 3 September 1944. The Brussels Airport, in the suburb of Zaventem, dates from the occupation.