RESO is a series of underground and covered pathways in Montreal linking 69 destinations, 52 are interconnected without the need to pay for a metro ride. The name RESO is a play on words for the French word “reseau,” which means network. Toronto made a similar move by calling their underground pathway system “PATH.”
Underground tunnel 
Overground pathway 
Shops in the tunnel 
Shops in the tunnel
The system isn’t entirely underground, I’ve visited sections that are covered walkways located above ground. Natural light is always a welcome break from the darker underground segments. Another quirk is a themed entryway that’s fashioned like a Paris metro entrance.
Shops in the tunnel
Maps and signs are abundant, helping pedestrians navigate the maze of pathways. Buildings connected by RESO have a clearly identifiable sign at street level, just like a metro entrance. In fact, the O in RESO is the Montreal metro logo to show that the system is connected by ten metro stations.
Paris-style entrance 
Geographic map 
Diagrammatic map 
Sign
In addition to connecting multiple shopping malls such as the Eaton Centre and shopping areas like the Montreal Central Station, there are also shops in the tunnels. It’s possible to spend an entire day in Montreal without seeing daylight.
Eaton Centre 
Exterior sign 
Connection to the metro 
Central Station
