Discover a safe haven of wide open spaces bursting with wetland nature. Fill your lungs with fresh air, stretch your legs and get ready to explore our extraordinary wetland paradise, whatever the weather! WWT Slimbridge is a wetland wildlife reserve near Slimbridge in Gloucestershire, England. It is midway between Bristol and Gloucester on the eastern side of the estuary of the River Severn. The reserve, set up by the artist and naturalist Sir Peter Scott, opened in November 1946.