When I first hit the road looking for odd-shaped buildings, one of my first stops was the Big Duck in Flanders, New York. I’d read about this giant bird for years and was dying to know what could possibly inspire someone to build a building shaped like a duck.

It turns out the answer was simple. Eggs.

Built in 1931 by duck farmers Martin and Jeule Mauer, the Big Duck served as an advertisement for their duck farm. Inspired by a coffee pot-shaped building they had seen in California, they decided their business needed a giant mascot of its own. At the time, Long Island was home to nearly three-fourths of the nation’s duck farms.

Constructed from wood, wire mesh, and concrete, the duck even has eyes made from old Model T Ford taillights that still glow at night.

The Mauers patented their creation, and it inspired countless imitators. In fact, architects still use the term “duck” to describe buildings shaped like what they sell.