If only we could be Mary Poppins for one afternoon—we'd soar over people's gardens, make way through the trees, maybe even befriend a few birds.

It turns out we can—well, at least the part about wandering through the treetops. Here are four "canopy walks" that make it easy to walk from tree to tree at an altitude typically reserved for birds. Blending innovative design with natural surroundings, each of these structures offers unusual aerial views of the trees, animals, ground, and sky.

Above: The Out on a Limb Tree Canopy Walk exists 50 feet above the ground in the Morris Arboretum at the University of Pennsylvania. Designed by Metcalfe Architecture & Design, the 450-foot walkway has a suspension bridge (that leads to a giant bird’s nest) and a large platform from which to view 92 acres of forest. Photo by Paul Warchol.

Above: A view from all angles. The Out on a Limb tree adventure exhibit has won several architectural awards in Pennsylvania, and is described as having created a balance between "perceived danger, actual safety, beautiful materials, and real trees." Photo by Paul Warchol.

Above: Located at the University of British Columbia Botanical Garden, the Greenheart Canopy Walkway makes a minimal impact on the trees--some of which are more than 100 years old--and the surrounding habitat. Extending for 1,010 feet, the walkway is composed of suspension bridges that incorporate a unique "tree hugger" technology. Photo by Roger Allen.

Above: Another view of the Greenheart; according to the University of British Columbia, one can see "a rare perspective of the natural beauty of the west coast forest canopy ecosystem." Photo courtesy of University of British Columbia Botanical Garden.

Above: Ziptrek EcoTours' TreeTrek offers guests a full view of the valley between two ski mountains, Whistler and Blackcomb, in British Columbia. The series of suspension bridges, treetop viewing platforms, and forest boardwalks are suspended up to 200 feet; the waters of Fitzsimmons Creek rush below.

Above: At the Atlanta Botanical Garden's Canopy Walk, a concrete pathway extends for 600 feet into the urban Storza Woods. The experience is described as "floating through the hardwoods," where spectators can see a wide variety of flora and fauna, from trillium to flowering trees to red-tailed hawks. Photo courtesy of Atlanta Botanical Garden.

Above: The structure of the Canopy Walk glows during the Georgia evening. Photo courtesy of Atlanta Botanical Garden.