“Let each man exercise the art he knows,” wrote Aristophanes 2400 years ago. That spirit inspired Italian immigrant construction worker Sabato Rodia, who spent 33 years building the Watts Towers in his spare time.

“I had in mind to do something big and I did it,” he said. He started work in 1921, and by 1954 he’d created 17 interconnected structures, some nearly 100 feet tall. His materials included broken pottery, scrap metal, bottles, bed frames, and seashells, and he assembled them using hand tools and window washers’ equipment.

Rodia finally gave up and left after repeated vandalism — local rumors said the towers were antennae for communicating with the Japanese. But when the city actually broke a crane trying to knock them down, it changed its mind and preserved the site as a state historical park.