Finally got a chance to visit here - put up some photos. Field notes follow.
I'd put this one down as one to visit mostly due to the lack of any scenery or sense of place until you get nearer the site, then the wonderful views to the west when you get to the site.
Very easy site to get to, park on the old A1 at the edge of the woods and walk in. Best to park north of the pathway shown on the OS maps as the road is very narrow here and there's nowhere to pull in.
Easy walk in through woodland but no obvious paths so some trail making required. As you follow the rising ground up towards the site it's easy to see that is wasn't built to impress when coming from the East. For a start there is much higher ground to the east. You'll see this as pass the 15th century tower. This is higher than the main site but much smaller in area. Had a look up here (hard going) and no obvious ditches or platforms.
As you pass the tower the ground flattens and you can see the end of the tree line in the West. While the site has been over planted with trees these are far apart and don't interfere with viewing the site.
Main features of the site are as follows:
1) Double ditch with bank between, very easy to see at the Eastern end, less obvious at the west end where there seems to be one larger bank and single deeper ditch. Bank around 1.5m high at the highest point near the western entrance.
2) Round/Oval in form, around 100m across at the widest point.
3) Number of features inside the ditches, bumps, hollows, etc. What looks like two well features - rectangular holes with iron railings over them.
Had a look round the web and this isn't a well feature but the entrance to an underground shelter that would have been used by the British resistance forces if the Germans had invaded in WW2 - link at http://www.coleshillhouse.com/heiferlaw-auxiliary-zero-station.php
That's a first for me!
4) What looks like two entrance gaps in the main bank, one to the East (South East), with the most obvious one at the western end.
5) Obviously built with a "western aspect" in mind. When you get to the Western entrance its obvious that the site would have been most impressive and most visible from the west where it would have been approached up a steep slope from the valley. Views from the site to the west go off to other sites such as Jenny's Lantern, White House Farm, Hunterheugh and the edges of Beanley Moor.
6) As with many "forts" in the area the site doen't look like it was mainly built for defence. From the East there is both higher ground and a wide area of flat land outside the ditches and the ditches here look the least impressive.
7) Possible "mound" feature inside the western entrance, but this also has the entrance to the underground shelter in it so could well be WW2 in date to hide the entrance.
8) Worked stone in the western wall - see photo - probably much later in date.
The views to the west are stunning and my photos don't do them justice - well worth the short walk from the car.
Easily access from the A1 north of Alnwick to the west of B6341. Unfortunately the site was planted with trees sometime after 1865. The earliest map on the Key to the Past web site shows the outline of the site before these were planted.
Listed as an Iron Age defended settlement the ring shaped enclosure has an outer ditch with two inner ramparts.