15 LONGEST Canals in the World Interesting! Canals are man-made waterways that often act as the backbone of global shipping and commerce. Some are big, some are small, and some are so thin that vessels have gotten caught in them for days at a time. With so many canals across so many countries, it can be tough to pick a favorite but they are all equally important. Sometimes even carrying clean water to local irrigation systems. So join us for today’s video, where we look at the top 15 longest canals! Don’t forget to leave a comment and follow us also on Facebook.