Hadrian's Wall facing funding crisis
The Hadrian's Wall Trust has said two years of "severe cuts" have put the long-term survival of the world heritage site in doubt.
Chief executive Linda Tuttiett said the trust needed an extra £170,000 a year.
Each mile of the wall costs £2,800 a year to maintain, according to the trust which has launched an "adopt-a-stone" appeal.
A fundraising website has gone live where stones, 162 turrets and 80 milecastles can be sponsored.
Ms Tuttiett said: "The budget for the maintenance of the Hadrian's Wall Path National Trail suffered a major reduction and now needs additional support. We are determined to maintain the trail in excellent condition."
Describing the wall as "a national asset", she said: "We want to give more people better access to all the site has to offer, from west Cumbria to Tyneside."
Ms Tuttiett said local authorities had responded to a call for extra funding, but feared their budgets would be further squeezed.
She added: "The world heritage site is 150 miles long and at the moment there is no proper monitoring system in place due to lack of funds.
"Another problem we need to address is the ongoing erosion of earthworks.
"Everyone thinks of Hadrian's Wall as a stone wall, but in fact much of the monument is made up of earthworks such as the vallum, the turf wall that preceded the stone wall, and the ditch north of the wall.
"These parts of the monument are affected by visitors and by livestock.
"We're aiming to raise £20m to secure the future of the wall over the next 10 years."