Egypt officially opened on Saturday the Grand Egyptian Museum (GEM), a long-awaited, billion-dollar showcase of pharaonic grandeur that Cairo hopes will revive tourism and boost its battered economy.

"Today, as we celebrate together the opening of the Grand Egyptian Museum, we are writing a new chapter in the history of the present and the future," Egyptian President Abdel-Fattah el-Sissi told a gathering of dignitaries, sitting in the museum's square.

Spanning half a million square meters, the museum houses around 100,000 artifacts — half of them on display — dating back more than six millennia.