1410 metres or so of suspension bridge crossing the river Humber just upstream of Hull, UK. At the time of construction, the longest single span bridge in the world. The reasons for its construction are shrouded in mystery, since very little actual traffic has much reason to use it (particularly after the completion of the M62 link to Hull which is used by most traffic going there from the south); indeed, most of the traffic on the ferry from Hull to New Holland which it replaced consisted of students attracted by the prospect of all-day drinking on the boat at a time when British licensing laws closed normal pubs and bars at about the time students get up and didn't open them again until after tea.
Was it an ill-conceived attempt to unite the historically separate territories of East Riding of Yorkshire and Lincolnshire Parts of Lindsey which were temporarily to become North and South Humberside in the not terribly popular local government reorganisation of 1971? Is it the first step in a secret plan to build a new North-South motorway paralleling the M1 and A1 and despoiling the empty but dull Wolds landscape? Or was it just the accidental coming to fruition of an idea some civil servant or government transport minister had when pissed?
We may never know.