Cosmati Pavement of Westminster Abbey. That pavement is worthy of some attention, especially if, like me, you are interested in the symbolic meaning of geometrial forms and their role in the great cathedrals of Christendom. (The following notes are abridged from the official website description. But PLEASE WATCH this excellent documentary about the pavement. Bear in mind that the image I have chosen is just a detail.)
The pavement was laid down in 1268 by order of King Henry III who had started re-building St Edward the Confessor’s Abbey in the new Gothic style in 1245. The workmen came from Rome, with a man called Odoricus at their head. It is 24 feet 10 inches (7 metres 58 centimetres) square, with dimensions calculated in Roman feet, and consists of geometrical patterns built up from pieces of stone of different colours and sizes cut into a variety of shapes: triangles, squares, circles, rectangles and many others. The basic layout is a four-fold symmetry, but in detail the variations are endless. No two roundels are the same. Of the four "orbiting" roundels one is circular, one hexagonal, one heptagonal and one octagonal. The infill patterns are all different.
The inscriptions that accompanied the design, now damaged, read in part: "If the reader wisely considers all that is laid down, he will find here the end of the primum mobile" and "The spherical globe here shows the archetypal macrocosm."
The round stone at the centre contains colours representing the four elements. It is on this stone that every king or queen of England was crowned. [See also here.]