Model of a Penrose staircase
1968
1968
1969
1968
1839 (original); circa 1988 (replica)
1969
(1962); 1982
2000-100 BCE
4000-2001 BCE
circa 1969
1969
1968
1968
1969
1990-95
1969
1968
1968-1969
1980-1950
1969
1903 (original); 1982 (model)
1969
6000-5000BCE
1969
1968
1969
1968
1959 (designed); 2001(made)
1968
1968
1969
1968
1969
1969
1798 (original); 1977 (model)
1968
1969
1968
1968
1968
1969
1969
1969
2050-1750 BCE
1969
1968
1969
1969
1968
1968
1968