Yes, that is a regularly used bridge. Near a remote Peruvian village of Yucay, about 20 miles (as the crow flies) from Cusco, there exists a narrow canal, no doubt made for irrigation. Farmers walk along a trail that parallels the canal to their small plots of land, which exist on the opposite side of the canal. On those plots, the farmers may grow maize or tubers, or they may have a cow or two grazing on the land. Regardless, the farmers access their land by crossing the canal on small, and often precarious, bridges, such as the one shown here. The rather crude doors, which exist with other bridges along the canal, are a puzzle; I can only assume that they help prevent trespassing. This photo was taken with a Nikon D3100 camera and Nikkor 16-85mm F3.5-5.6 lens.