The Leaning Tower of Pizza [U.S. Library of Congress] was among the gems found in John Margolies' Photographs of Roadside America, but the building in his famous photo no longer stands. The internet says there used to be multiple leaning tower of pizza restaurants around the US (Margolies photographed at least one other) but the Prince Pizzeria in Saugus, Massachusetts may be among the last. It's verifiably a vintage example of the form, too.
You can find it on the west side of US Hwy 1/Broadway, just north of its junction with Lynn Falls Parkway. I have a feeling they make great pizza here. I love the silliness of the name and design. Too bad it's not in my neighborhood!
See also: Unmanned roadside stores in Japan
