It has long been a mystery as to how the towering Great Pyramid was constructed more than four millennia ago. But a group of archaeologists from Cairo's French Institute for Oriental Archaeology and the University of Liverpool think they've cracked it. In an ancient quarry in Hatnub, where it's thought the pyramids' building blocks were made, the team discovered remains of a curious contraption, dating back to the era when the structures were erected.

Now test your knowledge: Can you guess these world-famous landmarks from their close-ups?

New secrets about ancient wonders we're just finding out