The Parthenon in Athens, Greece.

"It's the quintessential beautiful architectural form," Tara Imani says. "The Doric order, the use of entasis [a slight curve in columns] to make sure the columns didn't look spindly from a distance ... the siting on a hilltop — it gave us our initial ABCs of architecture that we keep trying to use and improve upon today."

Imani is the founding architect of Tara Imani Designs.