Kentish Town started life as a medieval hamlet just up the river Fleet
from St Pancras
. The river ran through it (where the High Street is now, winding off down Angler's Lane) and often burst its banks: there are records of its parish priest in 1200 complaining about the swampiness of his house and asking to move! By the eighteenth century, Kentish Town had better drainage, and was a place of pretty summer mansions for the rich, of tea-gardens and pleasure gardens; it remained a pleasant village until the expansion of London
in the mid-nineteenth century. Like its neighbour Camden Town
, its fields were razed to build long streets of white terraces, which over the next hundred years gradually decayed into slum housing.
As the nodes above note, it's shabby, it's got a lot of fast food outlets, and a fairly high crime rate - but it's still an expensive place to live. Its underground is fairly interesting: as well as the buried river Fleet it also has a ghost station, South Kentish Town, which can still be seen above ground on the corner of Castle Road.