We tend to think of North Africa as a dry zone (excepting the Nile Valley) and it is, with a strip of green on the Mediterranean and a sprinkling of oases in the Sahara. Not too long ago, though, it was greener. The Romans made use of this modest wetness by growing and importing vast amounts of grain.

Before the Romans there were Greeks and Carthaginians. The Greeks arrived from Santorini in the 8th century BC, settled in what is now eastern Libya, grew rich, and built great cities. The ruins at Cyrene are in a spectacular setting overlooking the shore. The Romans developed sites on and around those of Carthage and other Phoenician descendants. Riches flowed from North Africa to Rome, through North Africa to Rome, and occasionally back from Rome. The colors of Lepcis are sandstone and sea; the texture is coarse.

Inland is the desert and also groves of date palms which signify an oasis. The old city of Ghadames was built with fully and partially covered streets to resist the heat. The wealth of Central Africa passed through here on the way to the coast but Ghadames was made out of local materials -- sand, water, sun, palm wood, palm fronds, and whitewash.