Production designer Harley Jessup had long read about Paris's famous sewers, but when the Pixar team went to France for a firsthand viewing, they weren’t quite as evocative and romantic as envisioned. “So, because it’s entertainment, because we wanted to do something that was bigger than life and caricatured, we felt the audience would respond to us taking some artistic license and creating a grander, more Phantom of the Opera, Les Miserables type of sewer.“