(Image: Son of Alan)
Renzo Piano is the architect who designed London's famous Shard. His children range in age from 16 to 50, so he's been building sandcastles for a long, long time. He's put his skills to work to build sandcastles that are simple in outer form, but structurally ideal. In The Guardian, Piano explains what you need to do to build a professional grade sandcastle:
2 Start to dig a ditch where the waves have made the sand wet. Use your hands. Build the sand up to create the mass of the castle, which is really a little mountain with an incline of, ideally, 45°. You don’t need the ditch to be more than 30cm deep and 45cm wide, and the castle should be about 60cm tall.
3 Make an entrance in the ditch for the sea to enter. The magic moment is when the waves come and the ditch becomes a moat. If the castle is in a good position, you can watch the water ebbing and flowing for 10 or 15 minutes. To capture the image in your memory quickly, close your eyes when the water comes in.
-via Fast Co Design