The 'four colour map theorem' states that given any plane separated into regions, the regions may be coloured using no more than four colours in such a way that no two adjacent regions receive the same colour.
And here is one such example; Stamford in Lincolnshire, England, sandwiched between Rutland to the north and west, Cambridgeshire to the south, and Northamptonshire to the south-west. This is the only point in England where four counties meet.
And the Stamford Cross is in the centre.
The new Queen Eleanor Cross on the junction of Sheep Market and Castle Dyke, Stamford, Lincolnshire
(click image to enlarge)
Early in 2008, a new 10-metre high Eleanor Cross was erected in Stamford's old sheep market. The pillar is carved with roses to match the fragment of the only surviving piece of the original Medieval Stamford Cross.
The small piece of marble of the 13th century Eleanor Cross in Stamford can be seen in the town's museum.
It was here, in this stone-built town, that one of the most complete dinosaur skeletons in Britain was found. It is fifteen metres long (or 50ft for the metrically challenged). Coincidentally, many of the Eleanor Crosses were constructed with Purbeck marble which was formed in the Jurassic period, about 140 million years ago.
Stamford was also home to several sittings of parliament in the Middle Ages, and is still home to the Rutland and Stamford Mercury, Britain's oldest newspaper, which has a report and photo of the new Eleanor Cross.