Being the gigantic history nerd that I am, I love maps. This site has some really neat ones that are animated. My favorite is the one that shows the imperial history of the Middle East from the earliest kingdoms to modern times. It quite dramatically shows the myriad states and empires that were in control throughout the years. The best bit is of course, the Mongols, shown by a vast swath of maroon color spreading out from the Central Asian steppes to the eastern boundaries of Europe. How can you not be impressed?
There is another map on the same site that shows the history of major world religions. I like this map a lot too, although given that the site itself is titled “Maps of War“, there is the tendency to see the spread of these religions as a competition (look how much Buddhism spread! Wow, look at Christianity go!), which is not the impression that I wish my students to gain from viewing these maps. However, the religion map is particularly useful for showing the spread of the universal religions (Hinduism, Judaism, Buddhism, Christianity, Islam). It’s a great visual representation of a concept that is hard to grasp without the map.
By the way, in case you thought I forgot, these maps show the themes of state building and expansion (the imperial history of the Middle East) and cultural interaction (world religions) respectively.