This view of the Apex Corner roundabout shows the original Apex Garage.
The Northway Circus roundabout was built as part of general improvements to the road system in the 1920s.
These improvements, along with the North Circular Road, created the Barnet Bypass (A1) and Watford Bypass (A41) which met at the roundabout.
To serve the traffic which passed, a garage called Apex Garage was built on the roundabout. Such was its distinctiveness that 'Northway Circus' began being called 'Apex Corner'.
In time, Apex Corner took over as the name - it is now semi-official, used by Transport For London as the destination on bus routes.