Waterworks Corner is a signalised grade separated roundabout junction on the A406 in North East London, linked to a signalised "T" junction. It is named for being next to the local waterworks.
Original plan for the junction showing the unbuilt additional grade separation
The A406 originally took a circuitous route via what is now parts of the A104 and A503 around the southern edge of Epping Forest which necessitated a few TOTSOs.
During the 1960s plans were drawn up to dual and grade separate virtually all the North Circular Road. For Waterworks Corner this meant a more straighter route cutting through the forest. A significant junction was planned to cater for increasing amounts of traffic. Along with an underpass for the A406 the junction would provide direct links between the A503 and A406(E) along with a flyover to allow A104 traffic to avoid the roundabout. The complexity of the junction meant it would be built in stages with the A104 flyover representing the final stage.
The junction was built with the roundabout conforming to the original design but the rest of the free-flow links never materialised.
The links to the west were built first, with the underpass and links to the east being built later.