The Underground City (RÉSO)- the world’s largest underground city, officially known as RÉSO. Over 30 kilometres of passageways connect to all Montreal Metros and provide a refuge for tourists looking to escape the scorching heat of summer or the freezing winds of winter. With thousands of boutiques and apartments, 200+ restaurants and 34 movie theatres, this impressive underground city is regarded as both a major tourist destination and as an architectural wonder in itself.
Underground City, Montreal, Canada More than four and a half square miles make up this second city in Montreal—the world’s largest underground complex, with 4,350 hotel rooms, 2,727 apartments, 930 retailers, 68 metro stops, nine fitness centers, three skating rinks, two libraries, and a chapel.
From the street, all this appears as regular office buildings. I wouldn't have known if I hadn't taken the Metro (subway). But, with all of the snow, it is understandable! Imagine, dining, shopping, living, working and being entertained in this all winter long! I lived in a similar set-up in Toronto as a young woman, only I must say, this design is the real winner!