. >> reporter: the daily commute for calvin seibert is a long one. hour from his manhattan home to long island's rockaway beach. so this is your office. >> this is my office. >> reporter: not bad. with homemade tools, water, imagination and considerable skill, he turns one of the most common things in the world into structures that are anything but. >> i can't think of another art form that is more impermanent. even if it falls, it could collapse now, you know, right behind us and. >> reporter: you're okay with that. >> you got to be. >> reporter: the 59-year-old artist has been creating sand castles since he was a small boy. he almost chose a career in architecture, until he had a sudden realization. >> i don't really care so much about what is inside this thing. i like the outside as an object. >> reporter: so too do the children who gather around while he works. >> are you going to round off the edges. >> i have had some wonderful encounters with people, and that is definitely nice. but if they weren't here, i would still be here doing this. >> re