The British Library’s Flickr account is a bloody rabbit hole of lovely. And, all the images are being released for free without copyright restrictions*. I won’t guarantee that there is something there for every flavor of nerdery, but, if you don’t find your interests represented by something here, I think you need to seriously question your life choices.
*The British Library does offer you the option to purchase higher-than-screen quality images, which seems like a workable model to me.
The Finch and Pea 