"Jim Macklin" wrote:
Absolute lowest altitude, is below sea level in Death Valley

True for North America. But the Dead Sea is lower:

http://www.infoplease.com/ipa/A0001763.html

Dead Sea, Israel-Jordan, 1,349 ft. below sea level (–411 m)
Death Valley, Calif., 282 ft. below sea level (–86 m)

I'm not sure what aircraft was first to fly into the Dead Sea area to take
honors for the first lowest flight ever, but I know the Graf Zeppelin did
it in 1929, going to about 1000 feet below sea level. It didn't even need a
snorkel! :-)