A huge stone port a mile off Cardiff…built by the ancient kings of Britain….?
This post has nothing to do with Richard III, but concerns a great structure which, if it ever existed, would surely have been visible to him from the shore of South Wales. The intervening centuries have worn it down, of course, but he might—just might—have seen it.
We are becoming accustomed to important ancient discoveries along the Welsh coast of the Severn estuary. For instance, there were those Stone Age footprints, set forever in the hardened clay along the shore at Goldcliff, and the wonderful medieval ship discovered in the Usk at Newport. These are but two.
And now I have learned of a ‘huge’ stone port built by ancient British kings over a mile offshore at Cardiff. A what and how far out, did I hear you exclaim? Well, yes, that was my initial reaction, and it’s a fascinating thought, but could it possibly be true? You may relax, ladies and gentlemen, for I am not about to claim that it must have been the work of alien visitors; instead, I will resort to maps—Google, Bing, Earth, Ordnance Survey and others. One thing is certain, I am astonished that Giraldus Cambrensis forgot to mention it, and Nennius was most remiss not to list such a colossal undertaking among his Wonders of Britain!
The Severn Estuary is a dangerous place because it boasts the second highest tidal range in the world, the highest being the Bay of Fundy in Newfoundland. Things have changed since the Dark Ages, and now it is reckoned that the high water level of, say, the 5th century, would have been four metres lower than at present. I am not a geologist, historical or otherwise, so can only imagine that this might make a great difference to the appearance and integrity of the shoreline. My interest here is in the area off Cardiff, known today as the Cardiff Flats. As far as I can see, Cardiff never extended further south than the original shoreline, which surely means there was always mud on what is now Cardiff Flats? And that the highest spring tides still came up to the shoreline that Cardiff never dared to cross?
From the shore, the Flats reach out south for about a mile into the estuary, a vista of level, featureless, sometimes rippling mud that ends suddenly at the Orchard Ledges, which plunge down into much deeper water. At this physical point, in the time of the ancient British kings, it is suggested, there was built a great stone port. Its purpose was to defeat the tide, by always providing deep water for ships of all sizes. Especially, of course, military vessels.
Yes, the above image is how London is imagined to have looked at the time of the Cardiff port. But, of course, London has always been right on the confined bank of the Thames. The port off Cardiff is not only a mile or more out in the estuary, but was built of stone! It is an undertaking that even now would take meticulous and infallible engineering…and an awful lot of money and men! How long did it take? How great a workforce? Might the whole enterprise have been on a par with the Great Pyramid?
I learned of this harbour/port when reading The Holy Kingdom by Adrian Gilbert, Alan Wilson and Baram Blackett. This is a fascinating book dealing with the legends of King Arthur (among other things, including that there were actually two Arthurs), and I really enjoyed reading it. That is not to say I necessarily agree with all its theories and suppositions, but I definitely enjoyed it. The writing style is easy and inviting, and there aren’t any dull passages. According to the blurb – “As a result of research going back over forty years, the authors are able to reveal the locations of the graves of both Arthurs, the location of Camelot, the burial of the ‘true cross of Christ’ and uncover a secret historical current that links our own times with the mysteries of Arthur and the Holy Grail…” Yes, yes, I know that many of you will be groaning, but the book is still very interesting, if not to say fascinating.
Sometimes, whatever you’re reading, a passage will leap out and demand investigation. Then it stays in the memory, nagging away, until you do just that. The passage in question is the following, which I have taken directly from the book:
“….In the Cardiff area, which is typified by mud flats, the variation of the [Severn] tides means that the sea retreats for a very long way at low tide, leaving ships beached and therefore useless for military purposes.
“….Before land was reclaimed in order to build the Alexandra and Roath docks, the shoreline between the Taff and Ely estuaries was long and straight, corresponding to today’s high-water mark for spring tides. Beyond this high-water mark there is a low, flat shelf of mudflats extending for well over a mile to the Orchard ledges, where the shelf ends and the water deepens sharply. When the tide is out the mudflats are exposed. It was on the edge of these flats that we believe the ancient British kings built a great stone port in the sea, to overcome the problems created by the tides. Until recently there was a long, straight road running down through Splott in south-east Cardiff, called Portmanmor Road, a name deriving from either Porth-Maen-Mor, meaning ‘the Port of Stone in the Sea’, or Porth-Maen-Mawr—‘the Great Port of Stone’. It points directly at the centre of the harbour whose ruins, although not marked on modern Ordnance Survey maps, were included in those drawn up by local cartographers in the nineteenth centuries.
The above illustration has been inserted by me, and does not appear in the book. The resolution is not very good in the snip from the 1888-1913 Ordnance Survey map, but it shows that Portmanmor (various other spellings) Road acquired a kink at the southern end, and has these days been swallowed up by the docks and other developments. But the red dot-dash line follows the upper part of the road, and then reaches out into the estuary to the end of Cardiff Flats and the Orchard Ledges, where there is no visible sign of the stone port. It was from about this time that the port was omitted from all modern OS maps. And I don’t think that the above passage from The Holy Kingdom implies that Portmanmor Road extended right into the estuary, I have included the red line merely to show that the angle of the road would indeed reach out to the right point on Orchard Ledges.
“….The harbour is shaped like a gigantic horseshoe with its mouth facing outwards towards the deeper water of the Severn Estuary. The bulk of the harbour sits on the mudflats with its entrance stretching over the shelf. The distance across its opening is approximately 400 yards, and it is 500 yards deep (i.e. from mouth back toward land). Using this manmade harbour, ships could come and go as they pleased, regardless of the tides. It was certainly a remarkable structure and deserves to be explored archaeologically, for if there is anywhere in Britain where we could expect to find Dark Age wrecks, then this is it….”
I am unsure if what I have indicated with red arrows in the maps below is the harbour, shingle, or just the way the mud has settled as the tide ebbs. All I can say is that sometimes it looks as if made of stone, and sometimes not.
Well, after all that, I’m left with a huge unanswered question. Is there an ancient port still lingering for our modern eyes? Or not?
Severn estuary mud is another Wonder of Britain overlooked by Nennius. The Romans’ amazing concrete/cement (of which we hear many praises) is as nothing compared with what Sabrina can produce.
That Severn clay stuff is a curse on anyone whose garden is made of it (me, for one!) because it seems that no matter how much rain falls, the flower beds will have set solid within a day. But this is not so in the Severn itself. The retreating tide may expose miles of that awful grey-brown desolation, but there is no time between tides for anything to set. The stuff remains sticky, gooey, treacherous, mean-hearted and seemingly fathomless. Its sole avowed purpose is to grab your wellies and suck you down. Oh, and there are quick-sands too, just to make matters really jolly.
We still don’t even know how Stonehenge was created—Merlin’s name has been known to pass lips, and it surely would have taken his wizardry to conjure a 400 x 500 yard stone port, in the middle of the Severn Estuary, in that ferocious mud in the Dark Ages. Well, I’m not going to say it couldn’t have been done by mere mortals, but I confess I would really like to know how they did it.
And, of course, there’s always….
PS: Oh dear, it now seems that the Great Stone Port will soon be even more a thing of the past, because it looks to me as if the wall of the intended Cardiff Bay Tidal Lagoon will probably demolish what’s left of what might be a Dark Ages marvel.