See history unfold through Wikipedia through space and time. Every mention of a location or date anywhere in any article across all of Wikipedia was extracted and each location connected to the closest date to place it on a map. All locations mentioned in an article together with the same year are connected together. Thus, what you see is what Wikipedia had to say about each year 1800-present, which locations were mentioned the most, which locations were mentioned alongside each other, etc.
Interesting that there is a spike in action around the two World Wars, and then after the year 2000, information is everywhere !!!