We knock on door #9 inside the underground parking at Paris’ Gare de l’Est. The biggest network of miniature trains is waiting for us. The installation has been sitting at the heart of one of Paris' biggest train stations for more than half a century. The French Railways’ Friends Association (AFAC) presents more than 600 meters of miniature railways and several dozen members take good care of them during evenings and weekends. We meet Thierry, who’s retired and Rafael, in his thirties, who have both been playing around with miniature trains since they were 8 years old.