Windsor Great Cave is on the land owned by the non-governmental organization founded in which year?
Windsor Great Cave:  The land external to the main entrance is owned by the WWF (UK), and access is often denied by the World Wide Fund for Nature: The World Wide Fund for Nature (WWF) is an international non-governmental organization founded in 1961, working in the field of the wilderness preservation, and the reduction of humanity's footprint on the environment.
1961