The below information has been adapted from a very interesting website on the history of Headington. For more information about the history of Boundary Brook or Headington, please see http://www.headington.org.uk/history/index.htm .
In 1889, Boundary Brook marked the eastern boundary of the City of Oxford, and was the boundary separating Oxford from three neighbouring villages: Headington, Cowley and Iffley. Three of the boundary stones set up in 1892 are still in existence today; two of these are in Headington and the third is in Cowley (on Barracks lane). Boundary Brook marked the eastern boundary for 40 years, until 1929, at which point Headington, Cowley and Iffley were brought into the city boundary of Oxford and became suburbs of Oxford.
Boundary Brook starts just south of the present Cuckoo lane, and runs south down Headley Way. These days it starts underground, but up until the 1930s it was in the open, with steam engines refilling their water from it. The brook crosses the road at the point marked by the boundary stone, the point at which Headington and London Roads meet (hence the change in name here). The brook then continues underground, under the back gardens of residential houses to the east of Valentia Road, crossing Old Road half-way between Valentia Road and Highfield Avenue, finally surfacing after a short bend to the east. Interestingly the brook was piped underground for this section (alongside Valentia road) in the 1980s for health and safety reasons.
After surfacing, the brook runs south in-between Oxford University’s Old Road Campus and Mileway Gardens, passing underneath Roosevelt Drive. This part of the brook is currently part of the “Boundary Brook Wildlife Corridor”. The brook continues south past the Churchill Hospital and then turns south-east running along the edge of Southfields golf course. After meeting Lye Stream it makes a sharp south-west turn into Cowley, running down and under Barracks Lane. The brook then goes underground again near Marsh Lane, resurfacing on the south-west side of Cowley Road. Boundary Brook then continues towards “Boundary Brook Nature Park” by running under Rymer’s Lane and along the north boundary of Florence Park to Iffley Road. After passing the Boundary Brook Nature Reserve, the brook makes its final journey to the River Thames, reaching it just south of Donnington Bridge.
This multi will take you to the two boundary stones still standing within Headington; both of these boundary stones are situated at points where the brook runs underground. Unfortunately, the writing on both stones is illegible. There is a pay and display carpark near to the starting coordinates, or some free time-limited car parks on nearby roads (unfilled free parks can often be hard to find at certain times of the day).
N51 45.440 W001 13.181: The first boundary stone that you will visit is opposite Headley Way, at the meeting point of Headington and London Roads. At this stone, you will find a yellow fire hydrant sign nearby (to the left when facing the stone); you will need to take note of the numbers on this sign (number at top = A, 2-digit number at bottom = BC).
After taking note of the numbers on this sign, make your way to the second boundary stone.
N51 45.561 W001 13.259: The second boundary stone marks the corner point of the 1889 city boundary – the boundary ran eastward until this point, after which it took a sharp right-angled turn to the south. This boundary stone is more obvious than the first and can often be mistaken for another common marker often seen next to churches. If one wasn’t aware of the history of this stone, they might think that someone hadn’t paid any notice to the nearby warning sign. Above this sign is a 4-digit number, note this down: DEFG.
Once you have visited both signs and noted down the correct information, you will need to calculate the final coordinates using the following formula:
N51 45 . (A-F) (BxF) (A-D)
W001 13 . (G-C) (B+C) (E+G)
.