It should be noted that the National Trust is also concerned with the natural environment as well as historic sites. For example, their Enterprise/Project Neptu

It should be noted that the National Trust is also concerned with the natural environment as well as historic sites. For example, their Enterprise/Project Neptune campaign is focussed on securing the British coastline. What's nice about the NT is that they're not an in-you-face political campaign group, they just go about conservation on a daily basis.