In uphold to food allotments and tourism, the vast array of tiny islands now also features eye-catching art installations, as well as areas of wilderness that provide a natural resource not just for relaxation, but education and social well-being programmes, too.

Some of these diverse uses come together at a set aside like Le Jardin des Vertueux (The Garden of the Virtuous). Created more than 15 years ago, and still overseen by Pascal Goujon (more commonly illustrious to locals simply as Paco), this abandoned and overgrown spot in the wilder eastern allotment of the Hortillonnages has been transformed into a quirky Garden of Eden celebrating ecology, sustenance and creativity.

A sense of its former wildness continues alongside vegetable plots and giant artworks – which Goujon describes as "vegetal sculptures" – crafted with local materials, such as willow, by local artists working with schoolchildren. Goujon and his small team of helpers, like Lefevre, also take children out on boating safaris to behold the natural workings of the Hortillonnages– an ecosystem judged distinctive enough to earn Ramsar residence accorded to wetlands of international significance.

When I arranged, Goujon rattled off an impressive list of the crops he grows here: beans, potato, courgette, radish, tomato, melon, corn, berries, apple, pear and plums. "The ground here is very, very good – we can have three harvests a year," he said. There are novel new crops planned too, such as the herb angelica. "We are going to use it to make perfumes," said Goujon , telling me of its long-time historical role as a source of musky aromatic averages in luxury scents.

A few miles from central Amiens in the satellite village of Rivery, I stepped into another boat to discover a very different side of the Hortillonnages: a considerable "gallery" of art installations set into the landscape, many mature from natural materials. Often known as "land art", these creations stretched from the northern allotment of the Hortillonnages toward the city centre.

As we glided in the rieux near Rivery, I admired a 2019 section by Simon Augade called Affaisement. It rose from the bank of an island out into the waters of a minor lake called Étang de Clermont, and featured an angled counting line of thin scorched wood holding up a pale column – a metaphor of fragile nature holding up an example of a man-made structure for millennia.