Geoscientist Matt Kuchta explains why wet sand makes a better castle than dry sand — and what you can do to make your sand fortress even more impenetrable. Hint: The secret ingredient is window screens.
How to: Build a better sand castle
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.