This Gatlinburg tree canopy walk is the longest in North America, but it's not the longest in the world. The longest tree canopy walk in the world is Senda dil Dragun in Laax, Switzerland. Its bridges are just under a mile long, and it stands about 91 meters tall. So, it's longer and taller than the Treetop Skywalk in the United States, but both attractions are worth checking out.