This week the annual National Council for the Social Studies Conference (#ncss2011) is in Washington DC and the US National Archives have created a virtual tour of DC’s past for conference attendees – or anyone interested in exploring DC’s past.

You can take the full Tour of the Penn Quarter Neighborhood on the Historypin site. Or if you’re in DC, download the Historypin app to your tablet or smartphone to see the photos in situ as you walk between the Walter E. Washington Convention Center toward the National Archives building and National Mall area. As you stroll down the main corridor and sidestreets of 7th Street NW, the Historypin app will use your GPS location to suggest images along the route where you can stop and view historic photographs and documents from the past, juxtaposed with modern scenery. Stops include the nation’s first telegraph office and Ford’s Theater in 1865.

For more from the US National Archive, have a look at their blogs, follow them on @USNatArchives and check out their Historypin Profile.