Plato's Cave - 16th Century
Go here for a great, interactive explanation of Plato's allegory, The Cave
Erika Rothenberg - Freedom of Expression National Monument 1984
Erika Rothenberg - Another Century of Progress 1999-00
Unknown Artist- Evolution Of Man
Leonardo Da Vinci - The Madonna of the Rocks (version rejected) 1483-86
Leonardo Da Vinci - The Last Supper 1498