The Vizcaya Museum & Gardens in Miami, built by agricultural industrialist James Deering in 1916, is located right on the coast in Miami, and has a 'stone barge' placed in the water which acts as a breakwater and protection for the mansion. This stone barge is a work of art in itself, with a number of mermaids, at the bow and stern of the barge, and on top of the barge. It was created by American sculptor Alexander Stirling Calder between 1917 and 1919. map
Note the wings on the mermaid statue above. The mermaids at the barge's bow and stern have wings, whereas the much smaller mermaid atop the barge does not.
Villa Vizcaya on the whole was designd and built to look like a Italian villa that is hundreds of years old. So the materials, like the stone on the barge, are weathered materials that look old on purpose.
● The Mermaids of Earth coffee-table book: See page 114 in the book about this sculpture.