Oh my. From the Guardian: Carpet of stone: medieval mosaic pavement revealed.

The wraps have come off one of Westminster Abbey’s least known treasures, a medieval marble pavement foretelling the end of the world, while conservation experts consider how to preserve the ancient stones for the next 740 years.

Few modern visitors have ever seen it, although since 1268 kings and princes, queens and cardinals have walked across a symbol laden mosaic as intricate as a piece of jewellery.

It is made up of rare marbles and gemstones, including some recycled from monuments 1,000 years older, and pieces of coloured glass, set in complex allegorical patterns into a framework of Purbeck marble cut as intricately as a jigsaw puzzle.

"When this floor was new it would have blazed with colour," Vanessa Simeoni, the abbey’s head of conservation said. "The materials were chosen for their brilliance and shine, and the quality of the craftsmanship is actually shocking, the ultimate that could be achieved."

The mosaics are known as Cosmati work, after the four generations of a Roman family of marble workers who perfected the technique. The Westminster one, regarded as the finest north of the Alps, uniquely has an inscription boasting of its makers – and a cryptic message about the end of the world. [continue, see photo]