One of the significant finds was at Barningham Moor
More than 100 new examples of prehistoric art have been discovered carved into boulders and open bedrock throughout Northumberland and Durham.
The 5,000-year-old Neolithic carvings of circles, rings and hollowed cups, were uncovered by volunteers.
One of the most interesting discoveries was an elaborately carved panel on Barningham Moor, near Barnard Castle in County Durham.
English Heritage now wants to extend the project to Cumbria.
Kate Wilson, inspector of ancient monuments at English Heritage, said: "We know virtually nothing about this art. That's the exciting part of this discovery.
"What we need to do now is to discover how this art relates to other prehistoric features in the landscape.
"We are talking about very simple and abstract art, using circles, lines and triangles. Mostly the designs are pecked into stone in the shape of simple cups and rings."
Archaeologists have discovered thousands of examples of prehistoric rock carvings in the area in recent years.
Many feature on a website backed by Newcastle University, which includes about 6,000 images.
Ms Wilson added: "We are sure there remains a lot that is still undiscovered in Cumbria."