|photos by Calvin Seibert [via Flickr]|
Sand castle artist Calvin Seibert created these modernist structures sans blueprints, designing on the fly and using two simple plastic putty knives and a five-gallon bucket. Each sand castle can take Seibert anywhere from four hours to a couple of days to complete, only to be captured in a photo and then washed away by the waves.
You can view more of Seibert's work on Flickr.
[via Smithsonian and Colossal]