Perhaps a bigger surprise than the double forts on the top of Bewick Hill are the twin Second World War pill boxes which share the summit.
There is a current debate in archaeology about whether hillforts were defensive or were built to impress the neighbours.
If they did have a defensive function, then Bewick Hill is home to structures with a similar purpose separated by about 2,500 years. So what's new?
One of the pill boxes faces Bewick Moor and the other the plain of the rivers Breamish and Till.
Three years ago, archaeologist Stewart Ainsworth carried out a survey of the Northumbrian coastline between Craster and Dunstanburgh Castle, noting the complexity of Second World War defences as it was feared that wide beaches such as Embleton and Druridge Bay's invited German invasion.
He says: "In the very early days of the war, it was thought that an invasion could happen on the Northumbrian beaches and parachute troops could land on the moors.
The Bewick Hill pill boxes were part of a very long and complex set of defences."
The defence works constructed in 1940-41 were the most extensive ever built in the history of warfare in Britain. At the Second World War peak, about 11.5 million acres were under some form of military control. An estimated 28,000 pill boxes were built, of which one fifth survive.
Alan Rudd, of Tynemouth, is a member of the Fortress Study Group and reckons that about 200 pill boxes still stud the Northumberland landscape.
The Bewick Hill pill boxes were part of "stop lines" which ran from Wooler to Belford and Wooler to Alnwick, via Eglingham.
Wooler itself, at a "choke point" on the A697, was ringed with pill boxes.
Stop lines were designed to slow down the enemy long enough for forces to be gathered for a counter-attack.
"The pill boxes on Bewick Hill would stop troops cutting across the high ground," says Alan.
One stop line was a series of defensive positions on the bridges over the Tyne.
A second line ran along the River Coquet from the west of Rothbury to the sea.
A third and very strong stop line shadowed the River Wansbeck. Here, a listed pill box next to the early medieval Mitford Castle echoes the juxtaposition of the pill boxes with the hillforts. "The pill boxes face north because it was believed that the Germans could invade north Northumberland and strike south," says Alan.
They could also have struck across country to Carlisle, with no significant settlements to impede progress, to cut Britain in half.
"This would have had a dramatic effect on morale," says Alan.
"Northumberland is full of defensive structures such as pele towers, castles, Hadrian's Wall and pill boxes and they were built for a similar purpose - to slow people down or control movement.
"People don't realise that there is one pill box over the hill and one over the next hill. A number have been lost because they were in the way of development, but the Bewick Hill pill boxes should be safe because they are in the middle of nowhere."
They should remain at least as a memorial to the graft of the men who built them.
"Around five tons of concrete would have gone into each of the Bewick Hill pill boxes and would have had to be humped up the steep slope by hand," says Alan.