A road of two halves, one known for its path along the top of Portsdown Hill Road, and the other forming the run up to it.
Starting at a junction with Portchester Road, Downend Road initially formed the boundary of Downend House on the land to the west, now given to the housing area of The Ridgeway. To the east was East Cams Farm.
Originally mapped as Downend Lane (until about 1910), from here it took an uneventful and slightly meandering path up the hill. The stone building was a lodge built in the 1930s, with the next houses arriving in the 1940s. The Thicket was the entrance to the prisoner of war camp (E251), many of the residents of which would become visitors to the local area and eventually residents. The railway bridge was built in 1889 and there used to be a chalk pit beyond it which remains noticeable on aerial views to this day.
At the end of the 19th century a Whiting Manufactory was built on the east side of the road. This was joined by a chalk pit, and later Ellerslie House which went on to become the squash club and then the full health centre.
The alignment of the next section changed considerably when the M27 arrived in 1976. Originally it followed much of the same course, which would have been expensive to bridge the new motorway at an angle and disruptive to replace the new road. Instead a new bridge was built considerably to the west, and the alignment of the old road remains just visible in the lines of trees and abandoned sections of road within the new recycling centre on the hill.
Wallington Military Road was built in the late 1800s, built to connect the forts, and quickly became the main route to the top of the hill. This was severed by the motorway and redirected as a private access road around J11, but as part of the realignment of Downend Road a small section of it now lies abandoned. Cornaway Lane originally joined here.
At the junction with Swivelton Lane, the road crosses the path of a little-known abandoned railway. It went from the Delme Viaduct to Fort Southwick. The only evidence of it is where it loops around south of what's now the car park for Fort Nelson; here there are two rows of bushes about a railway's width apart. You'd miss it if you didn't know what you were looking for.
Before the Military Road was built, Downend Road only lasted as far as Portchester Lane. Hill Lane was originally connected to Portsdown Hill Road by four different roads: Nelson Lane, Skew Road, the straight path of Hill Lane, and an unnamed road that now forms a tiny section of Anson Road. Each of these were removed when the M27 was built, and replaced by one bridge on Skew Road, although the paths can still be seen if you know what to look for.
The subject of the forts has already been extensively covered by another site.