It took a lot of sand, maybe 100 bucketsful, and a lot of time. She was there soon after dawn and the sun was low enough to dip behind the lantern room of the lighthouse by the time she finished. Except for a short break to eat the paste sandwich she had made the evening before, she worked almost all that time.
It wasn’t very artistic, not really. Her plastic bucket had castle turrets in the base, so she turned out tiny crenulated castles and then had to smooth the top into a mound each time. She created a donut-shaped mound two castles high with a flat centre area about the same size as Grandma’s table. The table she hid beneath to avoid dragons, to trick elves and to enchant princes.
She left a gap in the mound two castles wide, so she could move freely from inside to outside and back. She topped off the donut with more layers until it was level with her hips. Sitting down, she checked the height again and could see over the edge easily. There was enough room inside to drop down and hide completely but pop up again without hindrance.
Using her red spade, she dug a trench all around the outside of the donut, half a castle deep taking care to include the gap she had left in the wall. The retreating tide gave her short legs a 30 stride walk to fill the castle bucket with water. The distance was 38 strides before the moat was full to the top.
She took eight loose-packed castles inside the walls and piled them ready to fill the gap, then brought one more castleful for luck. She knelt inside and began packing sand into the space until there was no sign where the entrance had ever been.
She sat in the courtyard and could see the moat that surrounded her, the walls that protected her and she felt safe. The dragons would never see her. The elves would be fooled into thinking she wasn’t there. The prince would be certain to kick down the walls in one go.