Yes, the convention center area is close to Old Montreal. Walk toward the river, but don't get discouraged when the first section of the city you see seems deserted. That's because the Banking District is in between the Palais and Vieux-Montreal, so there's a sort of dead zone of a couple of blocks you have to traverse before you head down the hill and toward the river. During my brief walk through the area on the trip I made a couple of months ago, I saw lots of things to look at and plenty of places to eat. I'm only sorry I won't get to try all of the great-looking restaurants.