So with my #urbanprehistory 'Hon. Corr. for Swindon's Roundabouts' hat firmly in place, here's a brief intro. I'm saving the more interesting specimens for future twittering, but I thought I'd start with a quick overview of the local collection beginning with this one (1/18)

which obviously raises questions about the various theories and reconstructions offered for the likes of Woodhenge. What if the postholes held giant pencils? What if the sarsens represented outsized erasers? Monuments not to astronomical knowledge but to, say, literacy? (2/18)

I'll return to the occasional presence of a megalithic component at these sites in a while, but first that overview, beginning with the simplest - the basic circle of paint, usually as here with nothing else of interest whatsoever in the vicinity. Lots of these, including (3/18)

some of the rarer oval and multiple-circle examples. At the other extreme, some are vast, supporting their own developing and unique ecosystems, isolated from their suburban surroundings by a sea of tarmac (or whatever that dark grey crumbly stuff currently used is) (4/18).

Others are more sparsely vegetated. (5/18)

Many, however, fall somewhere between these extremes, often with clear indications of regular maintenance, particularly near the more upmarket car showrooms (6/18)

while others can only dream of the possibility of a bit of greenery and the attention it might bring (7/18).

The frequent presence of a central grassy dome gives a barrow-like quality to many, but with two or more lanes of non-signalling traffic instead of an enclosing bank and ditch. This one, over 60m across (according to Google Earth), is among both the largest and simplest. (8/18)

Some mounds are surrounded and retained (protected?) by a stone kerb - I hesitate to use words like 'peristalith' (actually, I didn't, did I) - its presence possibly due to the type of vehicles anticipated. Clearly further analysis needed. Anyway - the megaliths... (9/18)

Large stones are a common sight around Swindon, and not just on roundabouts. Some, I suspect, have been in place for much longer than others. @urbanprehisto has written about this kind of thing. I'll save my comments for some specific, unusual, cases in future posts (10/18).

Swindon does have real prehistoric stone settings - the circle at Coate, for example, or this spot where in the 1660s John Aubrey saw an upright sarsen about 11ft high and "many others oooooooooooooo in a right line" (that's 14 stones, not a Frankie Howerd impression). (11/18)

However, most of Swindon's megaliths firmly belong to the town's 20th/21st century (AD) expansion, and, with a few remarkable exceptions (which I'll deal with in future posts) have never stood erect ('ooooooo...' etc). One that I will mention now is this one, which is (12/18)

actually the nearest roundabout to my house. Partly concealed from passing traffic by the overall suburban-garden-centre-tropical-island theme are a pair of standing stones. Generally, the prone stones on roundabouts show no signs of any planning in their arrangement (13/18)

(and no, I haven't checked the alignments yet. Sorry.) This roundabout also highlights another common theme - it's a point where older as well as current routes converge, something much more apparent on foot than from a car. For instance, parallel to the road heading (14/18)

north is a remnant of the earlier road, replaced when it could no longer cope with the weight of traffic. Now completely screened from cars by a thickening belt of encroaching woodland, it's mainly used by walkers, cyclists, joggers, and occasional farm traffic. It's a (15/18)

way in to a fragmentary network of old tracks, roads, railway lines, canal towpaths and riverside walks that offer alternative ways of exploring the town and its suburbs. If you look very closely, though, you can still see the concrete. Anyway, all that's by way of a (16/18)

gentle introduction. Next (no, I don't know when) I shall be attacking a particularly puzzling roundabout with the full weight of historical and archaeological means at my disposal (ie from home). Not this one. Another one a bit further along from here. (17/18)

I should add that I have absolutely no intention of saying anything about the Magic Roundabout. Google can help you out with that one. (18/18)