They set out to capture the forgotten France, the everyday architecture of emptied towns and overlooked villages – before their uniqueness is lost for ever. Eric Tabuchi and Nelly Monnier talk us through their vast photographic atlas

From the industrial north to the sun-baked south, Eric Tabuchi has spent two decades scouring the landscape of France with an obsessive eye. In 2008, the Danish-Japanese-French photographer created a beguiling series called Alphabet Truck by sneaking up on 26 different articulated lorries on the move and photographing the single giant letter adorning each one’s rear, from A to Z. In 2017, he made Atlas of Forms, a 256-page guide to all the shapes, from pyramid to polygon, the world’s buildings are based on. And in 2017, he joined forces with the painter Nelly Monnier, also his partner, to create the Atlas des Régions Naturelles.

This sprawling, unwieldy multipart portrait of a nation takes as its foundation the 500-odd régions naturelles, or non-administrative areas (a bit like British counties) into which mainland France is divided. Monnier and Tabuchi are slowly making their way around the country, arriving in each area with a minimum of preconceptions. First impressions are key, the idea being to shoot a few characteristic landscapes, then to work their way up through the area’s vernacular architecture, with everything dictated by local conditions.