Evolution of the concept
1) house of pleasure and summer house
2) type of architecture /garden (later on)
Origins: Folie comes from latin folia, which meant leaf, in old French: fol .
The word designated a summer house and refers to an extravagant building or construction;
In France, different from the English Folly at first, they sometimes took the form of romantic farmhouses, mills and cottages, as in Marie's Antoinette Hameau de la Reine in Versailles. During the Revival era, Italians will call it villa.
After the Regency, the word’s meaning will switch to designate a rich villa or a small house, where the riches, nobles or not, would entertain and "meet with their mistresses to have so fun"…
Later on, they evolved and copied from landscape paintings by painters such as Claude Lorrain and Hubert Robert, they had symbolic importance, illustrating the virtues of ancient Rome, or the virtues of country life, such as the temple of philosophy at Ermenonville.
Later in the 18th century, the folies became more exotic, representing other parts of the world, including Chinese pagodas, Japanese bridges, and Tartar tents.
Later under the Revolution and the Restauration the folies evolved again as gardens with attractions closer to the English concept of gardens, Vauxhalls
Some Folies around Paris, are very often found by the River Seine, in Bercy or in Auteuil, or in The bois de Boulogne.
In the second half of the 18th century, the Folies are built by the Chaussee D’antin, Faubourg St Honore and Montmartre.
Another beautiful exemple in the countryside is The Désert de Retz in Chambourcy.