Why? Clockwork Tunnels have a chance for danger rooms, Deconstruction Zones don't and often it is that there 2 of the same icons (even foreground/background colour!) are on the same floor and to check what level it is one has to open the gate map and hover over. Tough luck when after checking the map the level has rotated to the other with the same colour, you won't notice the change so you walk on to get in that Mechanized Mile and you land... in a Deconstruction Zone. It has happened to me plenty times and the fact that you have to hover over the icon on the gate map just shows how bad the situation is.