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Having taken pictures of more than 6 million miles’ worth of road, today Google is more than doubling the amount of global Street View imagery by adding all of its archive photography.

The company’s Google Maps Web application will now include a time machine feature where users can move a slider to see all historical images of a place. As much as possible, pictures of the same place have been aligned so they have the same perspective as one another.

In some cases, locations will have just a couple of versions of photos; in others, Google Street View cars have driven the same roads every summer.

That doesn’t mean you’ll be able to move the slider back and forth to see historical images of Rome compared to the present day ruins — Street View imagery only goes back eight years, at most.

But it does mean you’ll be able to play with some recent history, like the building of the Freedom Tower in Lower Manhattan, the building of the 2014 World Cup stadium in Fortaleza, Brazil, and the destruction left by the 2011 earthquake and tsunami in Onagawa, Japan.

You might also scan around to see how billboards and gas prices change, or what a place looks like in different seasons (though Street View cars mostly hit the road during daylight hours and when it’s nice out).

In the case of that view in Onagawa — according to Google director of engineering Luc Vincent, the guy behind the Street View project — you can actually see, because the GPS coordinates are locked, that the ground shifted three meters in the earthquake. It’s pretty insane.

“It’s a 3-D mirror of the world,” Vincent said of Street View. “Now with this, we’re finally adding the fourth dimension, time.”

Archive Street View will be available in 55 countries, except where it isn’t allowed, like in Germany, which only permits Google to post single images of 20 cities. There’s also no historical imagery of places like the Great Barrier Reef, which Google has only documented with underwater photography once.

The archive images will, for now, only be available in the Web version of Google Maps. Mobile support — which would be neat, because you could stand in a place yourself and look at it through time — will come later, Vincent said.

And actually, even with all the archival pictures added back in, there’s still tons of Street View footage left on the cutting room floor, which Google’s algorithms discarded as they pared down and snapped together the panoramas that make up the product. Before new Street View pics are posted, a process selects images that show the middle of intersections and head-on views of landmarks, Vincent said. It also scrubs out faces and car license plates.

Historical imagery was one of Google Maps most-requested features for years, according to Vincent. “The hard part of this is the data and infrastructure,” he said. “We just hadn’t gotten around to it.”

In case the feature isn’t live for all users yet (it’s not for me), here’s a gallery of before-and-after comparisons that Google spliced.