Installations by renowned international artists including Italy's Michelangelo Pistoletto and Portugal's Alexandre Farto have been erected in the sand under the great pyramids of Giza outside Cairo.
The fifth edition of the contemporary art exhibition "Forever is Now" is due to run to December 6.
The 92-year-old Pistoletto's most famous work, Il Terzo Paradiso, comprises a three-meter-tall mirrored obelisk and a series of blocks tracing out the mathematical symbol for infinity in the sand.
"We have done more than 2,000 events all around the world, on five continents, in 60 nations," said Francesco Saverio Teruzzi, construction coordinator in Pistoletto's team.
"There is an estimate that it's more or less five million people reached by the message of the Third Paradise."
The Franco-Beninese artist King Houndekpinkou presented "White Totem of Light", a column composed of ceramic fragments recovered from a factory in Cairo.
"It's an incredible opportunity to converse with 4,500 years -- or even more -- of history," he told AFP.
South Korean artist Jongkyu Park used the measurements of the Great Pyramid of Giza to create the geometric structures of his installation "Code of the Eternal".
A thousand small cylindrical acrylic mirrors planted in the sand compose a Morse code poem imagining a dialogue between Tangun, the legendary founder of the first Korean kingdom, and an Egyptian pharaoh.
Farto, better known as Vhils, collected doors in Cairo and elsewhere in the world for a bricolage intended to evoke the archaeological process.
Six other artists, including Turkey's Mert Ege Kose, Lebanon's Nadim Karam, Brazil's Ana Ferrari, Egypt's Salha Al-Masry and the Russian collective "Recycle Group", are also taking part.
