Arc-et-Senans, the “Immense Circle”, a completed architectural utopia

It is not yet the ideal city as dreamed of by Claude-Nicolas Ledoux, but it comes close. The « Immense Circle » imagined by the utopian architect of the 18th century to complete the hemispherical plan of the royal salt factory of Arc-et-Senans, was completed according to very contemporary methods: ecological, educational and fun.

Built between 1775 and 1779, the Royal Saltworks was to be at the center of a vast innovative city project, a future commercial port on the Rhine-Rhône canal, bringing together housing for workers, stables and food gardens. In short, a kind of phalanstery, a century ahead of time. “For Ledoux, architecture orders the chaos of the world, emphasizes Hubert Tassy, ​​Managing Director. It is utopian in the sense that craftsmen should be as well housed as masters. »

But the man of the Enlightenment goes further: he also draws a town hall, a church, a temple, a courthouse, and even a necropolis resembling a spacecraft, the model of which surprises visitors to the museum as the Saline dedicated to the architect. This bold program never saw the light of day, although the plan was approved by Louis XV shortly before his death.

White gold, green gold

“What was to be kept from Ledoux? The treatise he published in 1804 speaks of the reconciliation between work and habitat, city and countryside, the architectural tradition of Antiquity and the Renaissance and the modernity of Rousseauist and Physiocratic thought. says the landscaper Vincent Mayot who imagined the project with Leïla Toussaint. Project managers of the “Immense Circle”, the two partners are former students of the famous Gilles Clément, whose thought and advice have irrigated this project in search of harmony between man and his environment.

The contributions of a heritage architect, an ecologist and a philosopher also made it possible to include the reflection in the long term. « The construction of the Saline results from the depletion of forest resources located near the water sources of Salins, the salt being produced by the evaporation of brine brought to a boil, explains Vincent Mayot. After the environmental abuses linked to the exploitation of white gold, it is green gold that we seek to highlight. »

On the 13 hectares of the Grand Cercle, 8 in the historic enclosure and 5 in the new one, there is an immense range of 31 gardens to make all the birds in the area chirp with ease. Classified as a sensitive natural area since 2010, the site is home to three species of protected birds, as well as natterjack toads and other bats in these green spaces maintained without pesticides or chemical fertilizers.

« Moving Gardens »

Even in the spaces of the first semi-circle surrounding the buildings, designed to be open to visitors all year round, “the gardens are reversible, with the idea that they can evolve with the elements, the passage of animals and… visitors! »laughs Vincent Mayot, who shows, in the Jardin du Vent, how the concrete gratings installed on the ground will allow surprise plants to hatch after their seeds have been swarmed by the shoes of people passing by…

In these “moving gardens”, according to the formula of the landscape architect Gilles Clément, which change form and must allow biodiversity to be maintained there, even to develop there, the walker can caress the barley with a mane, taste the fruits of the serviceberry, s intoxicate with the scent of honeysuckle, refresh yourself in a house made of earth, hemp and lime. A real pleasure for the senses coupled with a playful walk to do with the youngest who will have fun in the huts and rest in the hammocks.

The other semi-circle, brand new, is still not very dense, but it should accommodate ten thematic spaces for educational workshops for families who would like, for example, to learn about permaculture. Since last month, it has also hosted the 22nd Festival of Experimental and Ephemeral Gardens, which presents eleven projects inspired by the work of Gilles Clément and designed by landscape gardening students guided by the advice of Claude-Nicolas Ledoux: “Dare and you will succeed, dare: the example you set will bring forth new precepts which will purify the old ones. »