This egg-shaped observation tower in Germany’s Bavarian Forest National Park is part of one of the world’s longest canopy trails—and one of the most distinctive. Visitors reach the tower via a nearly 1-mile-long elevated walkway that winds around the tops of firs, beeches, spruces, and more at eye-level. From the 144-foot tower, built over three ancient fir trees, they can see the vast expanse of Bavaria’s forests and countryside. Not only do canopy walkways like this one give visitors a bird’s-eye view of the forest, they also allow people to experience nature without harming it.