Theda Bara, for instance, was a very famous silent star, but few know about her today. Most of her films were lost. Her most famous one, "Cleopatra", was lost. She made at least forty, and I've seen varying numbers that only about three or six remain.
Also some early Laurel and Hardys are lost.
You will probably be disappointed to learn that the exotic villa Bara built for herself here in Cincinnati, her hometown, was razed by its latest owner Xavier University just a few weeks ago.
Quite a few of the silent films show a lot of nudity, some of the women who became talkie stars after the censors kicked in, in the 1930s, did nude scenes.