Watch Online Free FlixHQ. The Wiels Marsh, located in Brussels, hosts a body of water that is crucial for numerous species of birds, amphibians, and insects, as well as adapted vegetation that has allowed local biodiversity to thrive. In this animated documentary, several speakers voice their support for this unique place. The directors trace the history of this natural sanctuary, constantly threatened by real estate projects, and highlight the work of the volunteers who ensure its daily upkeep.