Castle Mill Stream walk

An ‘Oxford City Water Walk’, outlined in an online guide, this makes for a pleasant, interesting and varied walk. We began it at Gasworks railway bridge (now a footbridge), where the Castle Mill stream enters the Thames, followed the mill stream towards Port Meadow, and then looped back to the start. Without having intended this, but as a result of detouring to avoid narrowboats where people were isolating, we did the top loop of the walk in the reverse direction to that set out in the guide. And rather than embarking on a new westwards loop at the end of the walk, we retraced our steps — because that final loop was the most familiar to us. So this was a (partly accidental) variant on the prescribed walk.

Mill stream and walk route on 1878 OS map (

Castle Mill Stream is thought to have been a medieval construction, like Osney mill stream which lies just to the west (there was once some conflict over water between the religious houses which ran the two mills). On older maps of the city, it’s the Cherwell and the Castle Mill Stream which hold the city in their embrace — the Osney Mill Stream (our Thames) lies too far beyond the settled area to figure. Castle and Osney Mill Streams shared the name ‘The Isis’.

Now Castle Mill Stream exits inconspicuously into the Thames between St Ebbes’ redeveloped housing and Oxpens Meadow. We tracked it back, crossing Oxpens Road and along the side of the new Westgate shopping centre, heading towards the castle.

The stream forms the boundary between two old city parishes; the compact St Ebbe’s to the east and the sprawling St Thomas’ to the west. St Thomas parish once extended all the way to Botley to the west and Medley to the north. Old St Thomas’ High St, at the city side of the parish, runs across the stream. This High Street is strangely orphaned in that it’s no longer the focus for a community, and its church and neighbouring charity school, which once stood at its end, have been severed from it by the Oxpens road (at this point named Hollybush Road). Surviving older buildings along the street suggest that this was a working community but with prosperous members. The red brick house was built in the 1790s for a brewer from a family of bargemasters; he also built a set of almshouses alongside.

As the almshouse provision suggests, there were plenty of poor working people living here too, in houses which have largely disappeared, though some model working-class housing survives in Osney Lane, parallel to the High Street.

Before it reaches St Thomas’ High St, the stream splits into two. The two together form the water system of the mill, leaving between them a little artificial island, Wareham (weir-ham) bank. The back stream disappears among the backs of houses; the walking route follows the main stream to the site of the old Castle Mill, which continued in operation until the twentieth century.

Thence it heads NNW, tracking the route of Fisher Row, once home to fishermen and later boatmen and workers on the wharves, whose family lives and occupational histories have been carefully reconstructed by Mary Prior.

Hythe Bridge Street marks the hythe, or landing place, where goods brought down from upriver were unloaded. Initially this was river traffic – grain, stone – but after the canal reached Oxford, the canal basin and wharves were located immediately adjacent, in what’s now a car park, and on the site of Nuffield College.

Above this street, the river and the canal run for a while in parallel. Here we veered off eastwards into the district of Rewley. Once there was more railway track here, alongside the ruins of Rewley abbey. Now it supports a good deal of new housing.

What’s left of Rewley Abbey (with new housing behind). From Castle Mill Stream path

Ducking under the low bridge by which the railway crosses the Sheepwash Channel (alongside the battered remains of the older railway swing bridge), we emerged by the Thames.

At this point we left the city environment behind as we headed north along the ait, a narrow sandbar, a beautifully shady place on a sunny day, dotted with wild roses, with the fields that occupy the western part of the floodplain across the river to our left, and Cripley meadows allotments to our right.

We almost missed a heron, poised on a tree branch, looking for prey, which then flew off, disgruntled by our presence, I think.

At the bottom of Port Meadow, by the moorings, we reached the point on the Thames where the Mill Stream first branches off, and turned to follow it south, past paddling children, ducks and ducklings.

Upstream from where the bridge now stands, where there’s now a cross-Thames bridge, a weir once obstructed traffic, until 1937. It seems there was never a pound lock here — a modern lock with two gates — only a flash lock: a gate in the weir that could be raised to allow boats to ride through: a challenge to river traffic, though punters could see it as sport. The weir contributed– it was suggested, when it was finally removed — to keeping the river above shallow and sometimes impassable. The practice seems to have been to circumnavigate it by cutting through the Duke’s Cut, above Wolvercote, to join the Oxford canal, head towards Oxford, then, if necessary, rejoin the river via the Sheepwash channel. Still, this would only have wored for smaller craft.

If they made it thus far, boats heading southwards down the Thames, towards where we stood, had to choose at this point whether to head down the Mill Stream, to the wharves around Fisher Row, or to proceed the way we had come, towards Bullstake Stream, or later Osney Mill Stream (the modern Thames), and either way towards the wharves around Folly Bridge, or indeed on down river. In the early days of the post-medieval trade revival, boats more often made the first choice; later, more often the second.

The path south, back along the mill stream, runs along the canal, which at this point parallels the Stream, passing along the back of what I remember as Lucy’s Ironworks, now relocated in Thame and Dubai, and replaced by apartments, and then along the back of Jericho, once an area of wharves for coal and other goods which came down the canal  – wharves which endured beyond the closure of the canal basin, closing only in 1992, and now — after long delay — also the subject of redevelopment. Until the nineteenth century, this was also meadowland. Jericho was constructed (among other things to house workers for Oxford University Press) on what were once known as Great and Little Bear Meadows.

And so back to Hythe Bridge St, thence (in our version of the walk) to retrace our steps to Oxpens Meadow and the Gasworks Bridge.

The walk starts on former meadow land, runs through an old commercial and industrial-riverine suburb, and then (had we done it in the suggested order), a later, canal-side industrial district, then loops through common land and back down a section of the Thames with a strikingly rural feel about it, before reentering the town. This edge of the town became urban between the sixteenth and the nineteenth century, but it remained physically close to rural and pastoral spaces.

Of course the pastoral and urban once came together close to the route of the walk, near our starting point, at ‘Oxpens’ itself: the name links to a cattle market which operated between 1932 and 1979 on what’s now part of the FE college. Before that – for a preceding century — cattle were sold from pens at Gloucester Green, now the bus station (though it’s of interest that the very detailed 1876 OS map of Oxford shows cattle pens by the Osney Lane railway footbridge, so the ox pens seem to antedate the market).

In effect, the network of streams at this edge of the floodplain define islands within islands. A large island is defined by the whole of the Mill Stream’s loop to the east of the Thames. That island is in turn divided by the Sheepwash channel into two smaller islands, north and south. There is an early reference to the northern part as the ‘isle of Cropley’ (as in the modern Cripley allotments), presumably because the slightly raised land stood out above flood waters. The southern part has sometimes been termed Osney island: it includes the ground where Osney Abbey and Osney mill once stood (across the river from the latticework of streets that forms New Osney, what we tend to think of primarily as Osney now). Then within Osney island, Wareham bank forms one more, tiny island of its own.

A short account of this walk, with a link to this post, appeared in the Guardian 6 August 2020 , as a result of which it’s now my most visited post. [Note this link may not work for non-UK readers]

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