The Ring of Bookan is easily missed, or at least I found it so when I visited the site in late July 2009, though I will blame the long grass of course. It's an important though probably over passed site unless one knows it's there (minus the long grass).
The Bookan henge lacks two features common to Brodgar and Stenness - an entrance causeway and outer bank. These, however, could easily have fallen victim to ploughing and farming over the centuries.
Within the ditch are a number of stones and a rough mound. It has been suggested that this is the remains of a cairn, but this remains speculation
Latter info source: Orkneyjar/Ring of Bookan.
Leaving the Ring of Brodgar the next feature is the Dyke of Sean, the old Stenness-Sandwick boundary down to the loch - on the other side of the accompanying burn the Wasbister disc barrow sits in the far corner of a usually rather damp field. Looking up to the north look for the big green mound on the skyline in the uphill field. This is the Bookan tomb. Take note of the field as this isn't seen when you approach the fieldgate. Follow the field edge up to the tomb and just beyond take the track right that goes by the west side of the quarry with the various [?lesser] Bookan cairns along its sides. Leaving these looking northward and slightly downhill you see the Skae Frue mound. Above this is the field containing the Ring of Bookan. You reach the gate before coming to Skae Frue. Follow the track that passes east through two erect stones and in a few minutes the ring appears to your left. The easiest way into the surrounding ditch is on the right where this meets the field edge and then on the east side is the lower side of the mound. From on top you have a complete view of all the hills comprising the 'rim' of the 'bowl' within which the "Great Sacred Monuments" sit. More properly from any high point on the 'rim' the Ring of Bookan is visible, even when the monuments aren't. Ante- or post-quem, eh !
The beggars have boxed it in, trying the old direct route but instead had to do a circular one through three fieldgates before entering by one almost opposite Skae Frue. Alas, though the Comet Stone points to it the Warbuster hill hides the valley below even if you took away the Bookan cairns from around the old quarry. No, it is Bookan tomb that dominates the view of the monuments below. On the other hand you can see why they built here - from on top you can see an unobscured 360deg panorama of the hills.
Sadly, not much to see here, except a bit of a rise in the ground. We attempted an approach, but a herd of very excited cows, with calves and the most enormous bull prevented us even entering the field. This herd meant serious business.
Second time I reached the Ring of Bookan. Knowing now where it was as I went up the hill past where Bookan tomb lay to the top there was its outline to my left, a long low mound with a cleft in the middle in which a rectangular stone is prominent. The first time I saw it was as an unimpressive but still high mound, two fields away from the road and with a big hollow interior in which I saw a large standing stone and some less distinct stuff besides. This time it was clear that it is in the first field and there is no central empty space.
Walking towards it I was pleasantly surprised by the size and excellent condition of the surrounding ditch, which put me in mind of Maes Howe (though later this ditch called to mind Stackrue Broch down the other side of the hill : perhaps this like The Howe not only goes forward to Viking times but back to to the Neolithic - the subterranean passage could have been put through a tomb entrance as with the souterrain there). The stones I had seen were on a platform-like area across the mound. There seems to be an area of grass on the central mound indicative of an henge-type entrance long gone.
Down on the hillside portion there are exposed the friable stones of whatever structure underlies the mound's exterior - this is so fragmented that I can't help wondering if the builders used some pre-existing natural for a starting point at least. From here you can see the decent-sized mound of Skae Frue (alias Wasbuster barrow HY282144) below.
It is not obvious to me whether the 'platform' is archaeology or excavation. There is quite a lot going on there, possibly more than one structure even going by what is immediately obvious/visible, and you could use up a whole film trying to make sense of it. The archaeologists are unsure whether this is a henge or a tomb but I feel it could have been both (if some tombs were based-on, or incorporated, standing stones then this brings them closer to multi-period henge development - there is a divergence from a common origin let's say).
Sorted out my confusion between this chambered tomb and/or henge and the Bookan chambered tomb further down. So much easier to find on CANMAP at higher mag - all visitors looking for particular sites (and ejits like me) should really check with this resource first, the archaeology is so thick on the ground in Orkney. My second attempt and I still misidentified. Going up the hill to Buckan Farm at the top I looked to my left and saw a big mound in the field with a couple of stones sticking up in the central hole. Thought to myself, oh I only have half a film left I'd better leave that for Stackrue, must come back and approach this tumulus another time. Then when RCAHMS finally came back online after the weekend I found out my 'tumulus' was really the sought-for Ring of Bookan!! Still, Stackrue Broch was well worth it.
Marwick records the tradition ("The Orkney Herald" 11/7/1888) that folk went to the Bookan farmhouse for "the road and perhaps the order of the [pre-marital and marital] services" (Orkney Norn for the former service being 'buikin').
At an OAS set of talks tonight audience shown an aerial photograph showing a cropmark [nearer Bockan than Buckan it looked] in a field on the opposite side of the road to the Ring of Bookan and being a circular feature of much the same dimensions to it. Given as a possibilty that this relates to a recorded flint scatter hereabouts, presumably a reference to the small brown & yellow mottled ground flint hammer from Bockan (NMRS record HY21SE 52). More to the point is that Bockan house was part of traditions centred round the two great circles and used to have some idols [possibly Iron Age, like those at e.g. Brecks of Netherbrough and Dale souterrain, rather than Neolithic ?]
If the folklore tradition is correct this would surely be the place for the ceremonies - perhaps adaptation for the same has resulted in the confused form visible today.
In 1849 it is recorded that the late Mansie Hay used the "Druidical circle of Wasbuster" as a law thing - think Tingwall by the Rousay Ferry in Evie. Perhaps the chamber was used in the adaptation or revealed by the work, so leaving it open to such deterioration that it did not survive to the present day in a recognisable state. Thomas' 1849 description would identify Mansie Hay's seat as the large triangular stone in the middle.
The alternative name of Black Hill of Warbister would relate this site to Viking vardr 'beacon' (as with The Wart in S.Ronaldsay, the Verron broch at Skaill Bay and the Point of Veron mound near Voy).
In 1883 the Ridge of Bookan (sic) was 136' across the interior with a sharply defined ditch 44' across and 6' deep. No mention of any chambers, just the stones present nowadays.
Captain F.W.L. Thomas in 1851 believed he detected 5/6 circles tangential to the central feature, these [indicated on his plan] about 6'D and containing prominent stumps of stone. He observed that the ditch remained dry in even the wettest weather. He saw evidence that someone had tried to cultivate the land here - the earliest form of Bookan (preceding Bûkan even) refers to bygga 'bere' [a barley landrace] as suggested for Buckquoy in Birsay.
In a talk at Orkney College the archaeologist Nick Card said that when he walked along the associated ridge it isn't until you reach the Ring of Bookan that you finally see down into the Brodgar peninsula , and that it was being suggested that it was placed here as the demarcation between a settlement behind it and the sacred monuments below .
I now think his remarks actually refered to the Bookan chambered tomb further down .