article_snippet.sent: Naours' underground city is a two-mile-long complex of tunnels with hundreds of chambers dug out over centuries in the chalky Picardy plateau. 
article_snippet.sent: Photographer Jeff Gusky began a three-year study of the tunnels last July, intending to focus on the site's medieval past - but stumbled on this more recent slice of history. '
article_snippet.sent: Naours underground city is a two-mile-long complex of tunnels with hundreds of chambers dug out over centuries in the Picardy plateau .
article_snippet.sent: Surprise find: Jeffrey Gusky began a three-year study of the tunnels last July, intending to focus on the site's medieval past - but stumbled on this more recent slice of history .