Answer a question about this article:
Imperial's main campus is located in the South Kensington area of central London. It is situated in an area of South Kensington, known as Albertopolis, which has a high concentration of cultural and academic institutions, adjacent to the Natural History Museum, the Science Museum, the Victoria and Albert Museum, the Royal College of Music, the Royal College of Art, the Royal Geographical Society and the Royal Albert Hall. Nearby public attractions include the Kensington Palace, Hyde Park and the Kensington Gardens, the National Art Library, and the Brompton Oratory. The expansion of the South Kensington campus in the 1950s & 1960s absorbed the site of the former Imperial Institute, designed by Thomas Collcutt, of which only the 287 foot (87 m) high Queen's Tower remains among the more modern buildings.
In which decade did the expansion of the South Kensington campus being?
1950s