As hillforts in Northumberland go, this one has to be in the top 3. Yeavering Bell sits right at the top of the Northumberland National Park and has a hillfort spanning its two peaks.
As there were paragliders circling when we visited, we couldn't get the drone out to have a better look, but checking Google maps, there is a large surrounding way around the whole top of the hill. A little cairn awaits you at the summit.
There are lots of ways to bag Yeavering Bell. The closest place to park is Kirknewton, but not sure there is actually anywhere to leave your car, so next nearest place is Hethpool. From the parking just pick up St Cuthbert's Way and follow that to the base of Yeavering Bell.
Follow the route above or find it on OS Maps. Just over 5km and 290m of climbing.
Alternatively if you want to start at Wooler Common and bag more hills including Tom Tallon's Crag and Newton Tors, while also bagging the Gains Law Trig Point, then follow this walk to Yeavering Bell And Newton Tors.