All old photos have a certain poignancy, as they are frozen views of a past that will never return. You can never take the same picture twice, not really, because time itself does not freeze.

"Stereoscopy 150" is a gallery of historic 3D stereo photos converted to anaglyph for 3-D glasses. There are 44 historic photos from various European and American studios. The website is Polish, but text is also provided in English, German, and Russian.

A "photoplasticon" was a device for displaying stereographs to the public; imagine a sort of giant ViewMaster that could accommodate 25 viewers at a time. According to the website, there are still four photoplasticons in Poland.

The view of Berlin above was shot in 1903 by the American Benjamin Kilburn studio. When the photo was taken, the church in the background was newly built, about as young as the four girls marching in the foreground. The church was destroyed by bombs in 1943. Anyone visiting the same spot now would get a view . I do not know whatever became of the girls.