Nantes' quirkiest sight is this fantasy world – a serious and seriously wacky workshop with mechanical contraptions galore displayed in plant-filled hothouses – where you can fly giant herons in La Galerie des Machines and prance around like a maharajah on a 12m-tall, 48-tonne mechanical elephant with a secret lounge in its belly. Outside, by the river, Le Carrousel des Mondes Marins (a gigantic funfair carousel) whisks you under the sea on the back of giant crabs, octopuses and other strange sea creatures.
Jules Verne would be smiling in his grave if he knew the next amazing project the dedicated team behind the Machines de l'Île de Nantes current project: a gargantuan tree called L'Arbre aux Hérons (The Heron Tree), sculpted from 22 steel walkways (the 'branches') and suspended gardens. Eventually a pair of enormous mechanical herons will nest at the top of the 36m-high tree waiting to take visitors for a ride. A giant mechanical spider will live in the tree – see him in La Galerie des Machines – and a prototype of a branch has already been built and doubles as the way out of the current complex.
The basic entrance fee covers admission to both La Galerie des Machines (where machinists demonstrate their different inventions, giant spiders and caterpillars included) and the actual workshop (where the fantastical contraptions are built); separate tickets are required for the 40-minute elephant ride and Le Carrousel des Mondes Marines. Advance reservations for the elephant rides are highly recommended.