There are certain times when dads come into their controlling own with BBQs, long car journeys and sandcastle-budiling among the most powerful transformations. But if you too were one of those youngsters who stood by hopelessly as your father lived out the twisted dreams of a megalomaniac architect during a day at the beach, then this one’s for you. Because your creations were good dad, but Calvin Siebert’s geometric sandcastles are brilliant. On his charmingly self-effacing Flickr page, Calvin laments the fact that he falls back on “old standby solutions” because of time pressures but let us stop you right there sir, because these are tremendous. Although the thought of you being given a six-week stretch to work your sandy magic makes us very excited. Kickstarter anyone?