The Louisiana Superdome is the home of the New Orleans Saints, and with a dome diameter of 680 feet (210 meters), it is the largest domed structure in the world.

Thanks to Andrea and Jeff Fuchs.

The 308 by 2,400 foot Olivenhain Dam appears to be nearing completion in this photo, although it’s still under construction (there’s a yellow crane at the centre).

As part of San Diego County Water Authority’s US$827 million Emergency Storage Project, the dam does not block a stream or river but instead boxes off a 200 acre man-made reservoir (to the north) which will be filled with 7.8 billion gallons of imported water. The project is expected to be completed in 2010 (more information).

Thanks: Papapenguin