How restorers are unlocking the secrets of the relics in China’s Forbidden City

A restorer works on the head of a mechanical doll that manually moves a fan that once kept the imperial family cool on the sprawling compound of the Forbidden City - (AP)

Inside the Forbidden City, within a lab-like workshop, restorers are undertaking a meticulous effort to preserve the sprawling palace's historical treasures.

A fragment of glazed roof tile, bearing a mysterious dark patch, undergoes analysis in a state-of-the-art X-ray diffraction machine.