Are we all settled comfortably? Good, then we'll begin.

wen1NOUN

1 A boil or other swelling or growth on the skin, especially a sebaceous cyst.

2 ARCHAIC A very large or overcrowded city: the great wen of London

Origin Old English wen(n), of unknown origin; compare with Low German wehne 'tumour. Oxford English Dictionary.

 “The Great Wen”, as a nickname for London, was coined by William Cobbett, an English radical and pamphleteer (9 March 1763 – 18 June 1835). He was a farmer and soldier, who became a great champion of rural England.

Portrait of William Cobbett, possibly by George Cooke, c. 1831, National Portrait Gallery, London.  

Wikipedia: Cobbett saw the rapidly growing city as a pathological swelling on the face of the nation. The term is quoted in his 1830 work “Rural Rides” — 'But, what is to be the fate of the great wen of all? The monster, called, by the silly coxcombs of the press, "the metropolis of the empire?' ". 

This notion of London, then, is of a pathology — a blight on England’s green and pleasant land. It is diametrically opposed to the idea of London as the mythical city where the streets are paved with gold.

Is London blight or bling? We may find out. We may have some fun on the way Join us! To quote from Peter Ackroyd's wonderful and mammoth book 'London — The biography':

"So we set off in anticipation, with the milestone pointing ahead of us 'To London' ".