While hard to classify as a proper building, the Blue Whale of Catoosa, Oklahoma — aka the world's most famous cement sperm whale with a waterslide jutting out of its side — is considered royalty in the world of kitschy roadside attractions. After all, the gentle leviathan is beached permanently right off of Route 66, the most iconic American roadway of all.
Built over a private pond by retired zoologist Hugh Davis in the early 1970s as an anniversary gift for his whale figurine-collecting wife, the Blue Whale was initially a family-only affair. But as Davis soon found out, when you erect an 80-foot-long marine mammal alongside America's most vacationer-heavy highway, people will pull over and gawk. And pull over and gawk they did. It didn't take long for Davis to open the Blue Whale up to the public and convert the pond into a proper swimming hole complete with a sand beach and picnic area. Other attractions, including a reptile zoo, followed. While the Blue Whale isn't quite the hotspot it used to be and the pond is more stagnant than swimmable, preservation efforts lead by the Catoosa Chamber of Commerce have helped to keep Oklahoma's most well-known cetacean on the map.