Sea waves are green and wet,
But up from where they die,
Rise others vaster yet,
And those are brown and dry.
They are the sea made land
To come at the fisher town,
And bury in solid sand
The men she could not drown.
She may know cove and cape,
But she does not know mankind
If by any change of shape,
She hopes to cut off mind.
Men left her a ship to sink:
They can leave her a hut as well;
And be but more free to think
For the one more cast-off shell.
Robert Lee Frost
http://www.poemhunter.com/poem/sand-dunes/