19TH CENTURY VENETIAN MANUFACTURE Walnut carved and shell-shaped Grotto piano stool. . Cm 42,50 x 58,00 x 47,00. The "grotto" furniture, often in the shape of shells or sea creatures, was originally created for the artificial grottos of the gardens of the noble palaces of the Venetian aristocracy. Sometimes painted or gilt, this fantasy furniture became highly sought after during the 19th century, highly appreciated by the eclectic taste of the turn of the century.