Maria Reiche, who spent half a century as the self-appointed guardian of an obscure pre-Incan culture's most mysterious legacy -- a vast, dazzling tableau of giant birds, animals, plants and intricate geometric patterns scratched into the stark desert floor -- died on June 8 in a hospital in Lima, Peru. She was 95 and was known as the Lady of the Lines.

To see the lines near Nazca, in southern Peru, from the air -- and there is no other way to make out the fabulous figures, some hundreds of yards across -- the vast tapestry looks very much like the haphazard markings on a giant child's chalkboard.

There is a monkey with a whimsical spiral tail here, a condor there -- a whale, a shark, a pelican, a spider, a hummingbird, an owl-faced man, a pair of hands, other birds and animals, flowers, and an array of geometric shapes. There is also a profusion of string-straight lines, some extending for miles, none suggesting an immediate explanation of why they were drawn.

After almost 60 years of intense, if highly speculative, scholarly scrutiny, it is hard to tell which is the greater mystery:

Why the valley-dwelling Nazcan people would decorate the surrounding desert mesas with figures so large their shapes could not even be discerned before the age of aviation 2,000 years later.