Oldenburg created this sculpture in collaboration with his boo, Coosje van Bruggen. So epic was their love that it could produce a giant safety pin. In fact, it gave birth to a whole litter of them. The pin at the de Young has a few siblings scattered around, including one at the New Orleans Museum of Art. 

Boiled down, their reasoning was: take a mundane object, supersize it, and voilá, art. 

About five years later, Scottish sculptor George Wyllie ripped them off with "Nappy Pin."

It balances precariously in the de Young's sculpture garden, so you can enjoy it for free. Don't stand too close; a sudden gust of wind, and you might find yourself impaled.