5 Mali Blunt (Mali) - a month ago
Huge, historic tunnel. Definitely worth seeing, and walking the distance that goes under the waterway. We went during a weekday, which I believe accounts for it being the amount of busy to educate yourself on how the locals utilize the tunnel, but not so busy that the the paths is immovable. The stairs and elevator up and down, give you a good feel to just how deep the tunnel goes. And yes, if you want to bike it, there is a special elevator for the bikers as well as one for pedestrians. The stairs are manageable too if you don't have a fear of heights. Just be mindful of the bikers pedestrians.