Halta, Definizione, lets you look at Botticelli's "The Birth of Venus" up close, like you've never seen it before. The site can be slow to load, but wow once it does!! You can zoom in and work your way around the entire canvas studying the base drawing, paint applications and color. Woosie.
I've seen the painting in person, but even then, I didn't see it like this. And there are several paintings available on Halta which you can study like this. Almost as good as being there. (You still can't smell the paint.)