One is the Flickr photo album from the Palestine Exploration Fund, which has been studying the area of historic Palestine (including parts of what are now Lebanon and Jordan) since 1865. Over 150 photos are visible, some quite fascinating:
View of the Temple Mount, 1864
Panorama of the Dome of the Rock, 1917 (notice the weeds)
Also, a recent re-discovery of artifacts from Jerusalem in the first century CE.