M25 motorway

The M25 motorway is the orbital motorway which encircles London, crossing (to the east of London, between Essex and Kent) the Thames via the [Dartford Crossing]?, which consists of the [Dartford Tunnel]? in a northerly direction and the [Queen Elizabeth II bridge]? in a southerly direction.

It is for the most part a three-laned motorway although there are a few stretches which are two-laned and a few (seemingly shorter!) stretches which are four-laned.

"Many phenomena - wars, plagues, sudden audits - have been advanced as evidence for the hidden hand of Satan in the affairs of Man, but whenever students of demonology get together the M25 London orbital motorway is generally agreed to be among the top contenders for exhibit A." --from Good Omens, by Terry Pratchett and [Neil Gaiman]?