The uncovering in Luxor this month of 12 statues with the body of a lion and the head of a man - sphinxes - reveals something concrete: how much humankind has left to uncover.
Sphinxes still riddle
The find is said to prove the existence of an ancient ceremonial avenue connecting the famous Luxor and Karnak temples. Such a "Sphinx Alley" has long been documented, but never discovered. The statues are inscribed with the name of the Pharaoh Nectanebo I, the founder of the last Egyptian dynasty, who died in 362BC.
Once a year, Egyptians were said to have walked the route carrying statues of the deities Amun, the supreme god king, and Mut, a mother-goddess, in a symbolic re-casting of their marriage. Cleopatra, the legendary Ptolemaic queen who left her hieroglyphic mark in Luxor, probably walked among them. "It maybe shows that Cleopatra brought Mark Antony or Caesar (on a journey up the Nile River) to visit Sphinx Alley," said Zahi Hawass, a renowned Egyptian archaeologist.
The sphinxes that WB Yeats wrote about endured "20 centuries of stony sleep". But the statues uncovered in Luxor, also buried for two millenia, show that a drive to know about the region's past knows no rest.
What more lies beneath the desert sands?