Using Google Street View’s historical imagery (and sometimes a bit of Bing imagery), the GooBing Detroit blog showcases some heartbreaking scenes around the city. For example, here is a series of photos from 2009-2013 on Exeter between Seven Mile and Penrose in northern Detroit.
The blog is both incredibly amazing and shockingly sad. I encourage you to check out the full blog to see the items that Alex has assembled on the page.
Activating it is quite simple. While viewing imagery in Street View, simply click the clock in the upper-left part of the screen (as shown in the image above) to choose a different time. Note that this feature is rolling out in stages, and you may not yet have access to it.
The imagery dates back to 2007 in some areas, and could be quite useful in a number of scenarios, particularly as the collection continues to grow over time. This feature is not yet available in Google Earth (only on Google Maps), but presumably will be added at some point in the future. However, Google Earth does have the incredibly useful historical imagery feature. Having both of those available in one interface will be quite nice!
Maps have seen massive changes over the centuries. From rough, inaccurate maps thousands of years ago to Google Earth today, maps have changed in amazing ways. An article from The Atlantic summarizes those changes by showing twelve different maps that helped change the world.
The list goes back to the year 150 with the map above from Claudius Ptolemy and ends with Google Earth, with many interesting maps in between.