Here is a link to an impressive web site of "Then and Now" photos which allow you to travel back in time from 2014 to 1944:
Directions:
Left click on each photo, or drag your mouse gently from left to right on the original photograph and it will merge into a photo of the exact-same location and view in 2014.
Drag it back to the left and you are back in 1944!
Then scroll down for more of the same.
http://interactive.guim.co.uk/embed/2014/apr/image-opacity-slider-master/index.html?ww2-dday
