There are what appear to be weird shaped tanks along the highway near the Denver International Airport.
I absolutely could not imagine what they might be for.

Cloudscape by Christopher Lavery – photo from flydenver.com
They are art!
A project by artist Christopher Lavery, Cloudscape is constructed out of corrugated metal and cellular plastic. Its function is purely decorative.
They are cute, but I still think they would make good storage tanks.
2017 Update: Cloudscape is now located along Interstate 25 at the Denver Children’s Museum.