The Nakagin capsule tower is a symbol of Japanese architectural metabolism and a prototype of a new way of urban life. Designed by architect Kisho Kurokawa, the tower appeared in Tokyo in 1972, made of 140 removable "capsules. The building was a striking example of the avant-garde architectural movement called "Japanese metabolism". The "capsule" structure was conceived as the embodiment of progress and harmony, practicality and technical ambition. Individual cells could be easily replaced as they deteriorated, so that the building could be maintained over time.