"The birthplace of modern conservation, Slimbridge Wetland Centre is the ideal place to get closer to nature."
http://www.wwt.org.uk/centre/122/visit/slimbridge/.html

"With an astounding array of wildlife from Water Voles to waders, hares to dragonflies, Slimbridge is home to the world's largest collection of swans, geese, and ducks. It is also the only place in the world where you can see all six species of Flamingo.

The vision of Sir Peter Scott, Slimbridge holds international significance as the headquarters of the Wildfowl and Wetlands Trust (WWT) and it is here that the world renowned experts of WWT Consulting and Species Conservation are based.
This leading conservation reserve of 325 hectares of internationally protected wetlands including a Site of Specific Scientific Interest (SSSI) a Ramsar Site and Special Protection Area (SPA) is managed by WWT."
See also https://pbase.com/tjm04/slimbridge10