Coming from NE England, I thought I was used to depressing dumps, including the town I was born in, South Shields, but, the list below either eclipse it, or, run it a close second:
Mablethorpe - A dump of a 1950's seaside 'resort'
Bridlington - as Mablethorpe, above, but, with more charvers
Blackpool - too horrible to even describe
Chatham - unbelievably grim
Hartlepool - dreadful place
Middleborough - or, indeed Cleveland in general, so, including, Billingham, Stockton, armed guard required
Hebburn - no longer a reason for it to exist
Workington - like Whitehaven, below, its one redeeming feature is, it is one of the start points for the C2C Cycle route
Whitehaven - a grade 1 dump, it's one redeeming feature is, it is one of the start points for the C2C Cycle route