Forget clocks and watches – overlapping present images with historic photographs is perhaps the most stunning and illuminating way to see what a difference a day (or week or month or year or decade) really makes. In some cases very little changes, but in other images you can see just how much can shift over a short period of time – from demolished structures and reconstructed buildings to entirely-altered streets and waterways.

These are wonderful photo superpositions.  To check them out, click here.