Take only memories, leave only footprints
Note: this quote is attributed to various people depending on which website you read.
When I converted this September 2014 image to black and white last night, the quote immediately came to mind.
In reality, the local environmental body (or council?) had used tractors and graders to cart loads of sand to the St Kilda beach, south of inner Melbourne, to replace the sand which was gradually being eroded away by strong tidal waters.