Talk about amazing Photoshop! Dutch historian Jo Teeuwisse has created a then-and-now project entitled Ghosts of War-France which features modern day France streets blended with WWII soldiers in the same location. Teeuwisse got her idea when she found 300 old WWII photographs on negatives at a flea market. She then got her negatives digitized and went to all the locations in France that were featured in the old negatives. She then photographed the same location and frame from the negatives and Photoshopped the two images together. This is absolutely amazing given the fact that she had to frame and find all the locations in modern day France that were in her old negatives. And then perfectly blend the images together in Photoshop. Here are some wonderful examples!
Truly amazing work! If you want to see more photos go to PetaPixel where I found the article.