Model of a Penrose staircase
1968
1968
1967
1968
1967
1839 (original); circa 1988 (replica)
1967
1966
(1962); 1982
1990-96
1965
1965
1966
1965
1966
1966
1903 (original); 1982 (model)
2000-100 BCE
4000-2001 BCE
1965
1965
1967
circa 1965
circa 1966
1968
1967
1968
1967
1968
1966
circa 1965
1968
1968
1968
1965
1968
1965
1965
1968
1968
1965
1968
1968
1968
1968
1968
1968
1980-1950
1966
circa 1966
1966