Icons of nobility, the massive, circular dovecotes of northern France housed pigeons rather than people -
Until the French Revolution stripped the aristocracy of its traditional privileges, only members of the nobility were allowed to keep pigeons. “To house the birds, magnificent castle tower-like structures were constructed. From the 13th century until the 1789 French Revolution, ten [of] thousands of these pigeonries existed in Northern France, yet today only a few hundred remain. After the French Revolution, many ‘pigeonniers’ were destroyed as symbols of the feudal past.”
Those that escaped destruction still dot the French countryside — large, imposing, nearly windowless towers whose interiors are filled with hundreds of small niches.
I have a few photos of these in my blog, there is a big one near us at Sauze Vaussais.