We started at the Eaton Shopping centre and finished at Complexe Desjardins which was near to our hotel. I found it quite interesting finding our way through the network of passage ways, although it is definitely not constructed to be a direct route from one end to the other. More likely it was designed to give direct routes between metro stations and the close surrounding buildings. During the journey we came across metro stations, food courts, art installations, wandered into a hotel reception and ended up walking into a vestibule of an office tower. Like other reviews have mentioned, signage and maps are not helpful in navigating the Underground City. We had to ask for directions a few times, and every time locals would always advise us to get the metro, I suppose to them walking is a waste of time. Even when we asked someone who worked in a metro station for directions they told us it was not possible to pass all the way through to Complexe Desjardins! Ignore the locals advice unless they can direct you. Luckily the porter at the hotel we walked into was helpful, and a security guard for one of the companies also helped. Its worth doing once or twice if you have the time, only realised afterwards there are dedicated tours on Viator, might take the fun out of it though.