Round the world: Why call "the most ominous reservoir in the world" the picturesque river Uorf in the English remote place

In the English remote place, in the heart of Yorkshire, there is absolutely innocently looking site of the river Uorf. It call Bolton Strid. Let the traveler who has appeared there be not deceived fine in the picturesqueness and seeming tranquillity by a pastoral landscape. This site call "the most killing reservoir in the world". Bolton Street carried away an uncountable set of human lives throughout all history of the existence. Besides, it is shrouded by very foggy atmosphere of ancient secrets and riddles... In more detail...