New Orleans, geographers say, has a great situation but no site. It is located right by the mouth of the Mississippi River, the nation's biggest waterway, and right by the center of the country's biggest petrochemical complex -- thousands of oil and gas platforms and scores of refineries and chemical plants.

There's an obvious economic and political need for a city there, except nature didn't give us any place to put it.

Now New Orleans has been largely wrecked by a hurricane, though most of the damage, the Army of Corps of Engineers now concedes, was due to its own mistakes -- the levees weren't overwhelmed by Katrina, but simply collapsed before a storm of a strength they were supposed to be able to withstand.

How can we rebuild this impossible but necessary city faster and smarter? Who should take up the financial burden? What lessons can we learn so that the nation and the region doesn't have to go through this again? --Charles C. Mann

(Read an excerpt from "The long, strange resurrection of New Orleans.")