Fun in the sun starts with sand and a pail. Just add water.

The biggest sand castle I ever saw was in a shopping mall. A wooden form was used to hold it up, but the sand still had to stick to it. What made it stick to the form? I wondered. Then I learned. The sand had to be kept damp. Spraying it with water several times a day kept the builders busy.

And so I discovered the secret to building the perfect sand castle: wet sand. Not too wet, just very damp.

Scientists tell us that grains of sand are tiny sharp-edged particles that rub together. Water added to damp sand forms little grain-to-grain bridges that stick together. When too much water is used, it fills the spaces between the grains and the sand falls or drips as in "drip" castles.

Drip castles are easy to make. First build two mounds of wet sand side by side, close together. Fill a bucket halfway with sand and the rest of the way with water. Or sit on the shoreline where the water is plentiful.

Take handfuls of dripping wet sand and let it run slowly through your fingertips, in long drips, all around the tops of the mounds you have made.

Next, hold one hand between the tops of the two mounds and begin dripping sand along the edges, first on one mound and then on the other, working toward the center across your fingers to form a bridge. Build it up higher until it holds up by itself.

It sounds difficult, but it really works.

Building a sand fortress requires a different process. You will need a shovel, plastic buckets, and some carving tools.

You still begin with a mound of sand, but this time it needs to be very big. Maybe half your size. And you may need a large shovel to pile up the big mound. As always, the sand must be wet – not dripping wet, just very wet.

Then pat down the mound all the way around with the flat side of your shovel. Make sure it is packed tightly. You don't want it to crumble before you even get started.

For a tall castle, you carve down from the top. Dig out windows and stairwells around and down the sides.

Save the building of the walls and bridges for last. Remember to keep the sand wet as you work.

Where we live, there is a sand-castle- building contest held every September. The contestants have two hours to build their project. Families, friends, and business people come from neighboring cities to participate.

Two hours isn't much time when you're building a structure with walls, turrets, bridges, and moats.

But then not everyone builds a castle. Some choose other subjects – mermaids, boats, animals, and cartoon figures. Some sand sculptors even spray their sculptures with food dye to give them a more realistic or humorous effect.

Sometimes the sand buildings collapse in the last few minutes. (Do you remember why? Right, the sand dried out.) We have watched this happen, but often the builders know exactly how to change the design and still make it look right – and just in time to win the contest!

But you don't have to be in a contest to have fun in the sun. The next time you go to the beach, remember to take along your tools.

These include large and small shovels, buckets, plastic molds, a spray bottle for water, a brush, and a large spoon or spatula for carving.

Along the beach look for useful items such as seashells or small pebbles for decoration or for eyes. Have fun!