The village of Naours, remarkable for its cob architecture, is mainly renowned for its incredible network of caves, dug out of the neighbouring limestone plateau. These shelters, of which there are many in Picardy and part of Artois, are called creuttes, boves or muches, meaning "hideout" in the local dialect. The underground city could shelter several thousand people and their livestock and has 2km of galleries, a square, 300 rooms, three chapels, cowsheds and a bakery with ovens.