Britain from Above is a gallery of more than 16,000 historical aerial images of the U.K. The imagery was gathered between 1919 and 1953. You can search the database of images by clicking through the interactive map. You can also search for historical imagery by entering place names in the search box. If you just want to browse the imagery, you can browse the galleries.
Applications for Education
One of the galleries in Britain from Above is titled "unidentified." The images in the unidentified gallery are not tied to locations. The unidentified gallery could be the basis of a challenging geography activity. You could have students select an image and try to identify the location that the image should be connected to.
H/T to The Google Earth Blog.