If you've ever wondered what it would feel like to travel back in time and walk the streets of San Francisco, this might be the closest you'll get.

Two developers, Dan Vanderkam and Raven Keller, had the brilliant idea to take all the old photographs from the San Francisco Historical Photograph Collection and put them on an interactive map. This map functions similarly to Google Street View, except for when you zoom in on a particular place it gives you photos from as far back as 1850.

The project, called OldSF, lets you manipulate a slider to change the range of years (it goes from 1850 all the way up to 2000). The pair have geocoded about 13,000 images.

Visit the site here, or look below for some of the best photos we saw from the 1800s, marked with their locations in the city.