Engineering the perfect sand castle is tricky even in ideal conditions. If you don't get the sand to water ratio just right, your majestic creation will collapse and wash away. Unless you're cool with cheating. In that case all you need is a jar of Brookstone's magical sand that's always the perfect consistency.
Remember that time you brought Play-Doh to the beach and it ended up getting all gritty? That's kind of what's going on here. Except Brookstone's creation is actually 98 per cent sand mixed with a non-toxic polymer that keeps it perpetually moist and mouldable.
At $25 a jar, or two for $40, it's a lot cheaper than packing up the family for a trip to the beach. And since it only sticks to itself, you won't have to worry about this sand getting into every nook and cranny.