The M25 motorway is one of the United Kingdom's motorways. It is an orbital motorway, 117 miles (188 km) in circumference, that almost completely encircles London (the gap is formed in the east, with the Dartford Crossing or the A282, linking two sides of the River Thames). It is said to be one of the longest city bypasses in the world[1]. In Europe, the M25 is the second-longest ring road after the Berlin Ring (A 10) which is longer by 5 miles (8 km).