The Museo del Prado in Madrid has long been one of my favourites - beautiful paintings, and they explain the context and narrative of most paintings in depth instead of the usual 'this is Leda with the swan, oil on canvas.' Now they're going one step further and displaying 3-D (or rather, relief) copies of famous paintings for blind people to touch. One of the visitors said it was like getting back his eyesight - he can now touch the paintings he remembers seeing as a child, before he lost his sight.
In my hometown, one area of the botanical gardens was designed for blind people, with fragrant roses and herbs, a guiding rail and explanations in braille. Apparently Kew Gardens offers walking tours for the blind, but something more permanent and structural would be nice. And perhaps the National Gallery could copy the Prado's idea? I grew up in a town with a high percentage of blind people, and one of my teachers was blind, so I'm always happy to see something that makes the world a better place for them.