National Geographic and NPR have fascinating story on Paris catacombs:

• Interactive Map of Paris Catacombs
• Jacki Lyden's story on NPR

Chicago's got it's own underground historyOf course there's the CTA's subways, but there's a lot more going on underneath us. Some of us learned about the Chicago Tunnel Company's 60 mile underground freight network 40 feet below ground in the 1992 Chicago Flood. The photo above is from tunnels at the corner of Randolph and State Streets.

And then there's the ginormous Deep Tunnel project of the Metropolitan Water Reclamation District, one of the largest civil engineering projects ever.

Like the Paris catacombs, Chicago has a story to tell of what we do with our dead, which reveals much about the city's history, development, politics. There's the mass grave of Camp Douglas POWs from the Civil War, the Couch mausoleum still in Lincoln Park from when it was a main cemetery for the city, and the current controversy over the cemetery where a new O'Hare runway is planned...For more on Illinois graveyards, visit graveyards.com.