Hard as it is to imagine, Dover once had twice as many mills along the river, plus tanneries and other supporting enterprises.
My fondness for old mills, by the way, did prompt a novel, Big Inca.
OVERLOOKING THE REMAINING MILLS
You never know what we'll churn up in cleaning a stall
Jnana's Red Barn 
You have a place called Dover? Was probably accidentally named – is Brythonic for On Water
Ours is in New Hampshire … make of that what you will.
Dover is a common town name across the U.S., though I know of none having white cliffs.
Much of ours was originally known as Cochecho Village or Cochecho Falls, using the Native inspiration.
like welsh dwr with an accent on the w