The sandy beach at Cleethorpes was very close, and a local playground. We built sand castles, of course, out of the wet sand at the edge of the tide. One of our favourite games, however, was to build a fortress of sand around us against the incoming tide. Placing ourselves several feet apart, we would each pile a circle of sand, maybe a foot high, and stand inside as the tide came in. It was always a thrill when the tide washed all around it with us inside, as small islands in the water, with the shore line behind us as the tide advanced up the beach.
The walls would start to fail as the waters surged, and we would use our toy spades to dig wet sand from beneath us to shore them up. It became more desperate as the waves grew stronger and it became ever more difficult to dig sand fast enough to maintain the walls. The ending was always the same. A surge of tide would breach the walls, sending water flooding into our positions. Screaming with excitement and mock fear, we would splash our way noisily back to the safety of the shore with our shoes tied around our necks to keep them dry.