Griffintown is the most thoroughly rebuilt square kilometre in Montreal: a famine-era Irish faubourg of foundries and stables that emptied out when the canal closed, then filled back up with glass towers in barely a decade. The walk is the seam between the two — brick under steel, the canal that explains all of it still running along the southern edge.
Start on Rue Notre-Dame Ouest among the antique dealers, then turn down to New City Gas, the cathedral-scale brick works that once made the gas for the city's streetlamps and now makes a nightclub's worth of noise. Past it, the stone footprint of St Ann's church marks the vanished Irish parish — a memorial kept as an absence, which is the right way to feel the place.
The Horse Palace stables survive among the condos; read the new glass over the old brick. Then drop to the Lachine Canal, the waterway that built everything, and follow the towpath west. End at Atwater Market's Deco tower on the bank — buy lunch, eat it by the water, and walk inland to Charlevoix.
