This was a bit tricky to find but worth the effort in the end.
Take the turning off the A68 signposted Great Swinburne. Before you reach the castle there is an area you can park near the public footpath sign on the left. Go over the gate and follow the path - woods on you right. When the path forks (in front of a large tree) go to the left and keep walking. You will soon see a stone field boundary wall on your left and a gateway into the field. Through the entrance and follow the tractor tracks up the field towards the brow of the hill heading left. The stone is visible when you get to the brow of the hill but NOT from the public footpath.
** As I was walking through the field I was stopped by a chap in a land rover who I assume was an estate worker. He wanted to know what I was doing and when I explained he reluctantly gave me permission to go to the stone although he did point out that there was no public right of way to the stone. Something I was aware of! **
Like the Matfen and Warrior stones, Swinburne has cups and weathered grooves. Most pleasing to the eye. Unlike all the other stones in Northumberland, this one is of a decent size.
Access isn't bad, though from the road, the track is bumpy, and there's a gate. There's a decent parking spot next to the ex-chapel at Ox hills, and the short walk allows the chance to have a deks at the strange terracing. Permission to sneak off the path can then be sought at Swinburne Castle, where the chap was quite pleasant, and more than happy to allow us to wander, once he'd assured himself we weren't going to carve out initials on the stone.
You can't fail to see this site when making your way to the Great Swinburne standing stone.
As you walk down the path towards the stone, the large terracing is along the bank on your left. Must say that they looked like medieval strip lynchets to me.
Perhaps more interesting are the two fairly well preserved Barrows right next to the same path at the bottom of the hill near the metal gate. They are only a short distance apart and are well worth having a look when visiting the standing stone / terraces.
The tumulus next to the path by the terraces was excavated in 1925 when charcoal and wood was found. Supposedly the stones on top were once the kerb, and traces of the ditch are still evident. It was decided the barrow was of Bronze age date. It used to be known locally as 'The Kings Seat'.
These terraces are listed as being artificial. They are fairly hefty too. I was expecting something on the scale of your average ridge and furrow, but these wouldn't be put to shame by the earthworks on one of those big southern hillforts.
They are complemented by the strange linear rock outcrops to the north of the thin track down from the A68. I suspect similar outcrops underpin the terraces.
If you park near Swinburne Castle the first bank is directly in front of you: walk down the public path the rest are easy to find.
Not easy to tell if these banks were built or natural, and the terraces carved in.
Didn't see a soul here, the only noises were dogs, presumably kennelled near the manor house - quite eerie.