Environment Editor Tony Henderson visits a venture not to be mocked.
As a legacy of its centuries as a frontier zone, the North-East has an array of fortifications from defended farmhouses to towers and castles.
By the middle of the 18th Century there was hardly a need for any more.
But Sir Walter Blackett of Wallington in Northumberland couldn't resist adding to the line up.
He built a mock castle, and later a fort, on crags on his estate and today they still stand as picturesque curiosities.
Sir Walter inherited his uncle's estate at Wallington in 1728. It was mostly moorland and fell, with few trees and crossed by cart tracks.
His thoughts turned to drawing up a plan for major improvements and in under 30 years he had accomplished his great task.
He built bridges, roads which could take stagecoaches, created fields and farmsteads, and planted woodlands.
He also turned to the leading architect Daniel Garrett, who began the remodelling of Wallington house in 1738.
Sir Walter was not afraid to dip deep into his pocket for his grand scheme. After all, his expenses in his election campaign as an MP in 1741 totalled a staggering £6,319.
After shaping the landscape around his home, he switched his attentions to Rothley Crags to the north of his estate, around which he began to fashion an enclosed deer park.
The park was bounded by two new roads - the Hexham-Alnmouth and the Morpeth-Elsdon turnpikes, which met at Rothley Crossroads.
Rothley Park would provide a link between the tamed landscape of the Wansbeck Valley and the wilder moorland. Sir Walter also created Rothley Lakes by damming a stream and surrounded the feature with extensive woodland planting.
One of his pleasures after dinner was to drive to the lakes, which are now bisected by the B6342 Wallington-Rothbury road.
The western part of the lakes is run as a nature reserve by the National Trust.
The walls of the deer park, which survive although reduced in height, would have been a big job in themselves.
But by 1774 they must have been complete as there is a record of Squire Widdrington of Longhorsley providing 30 deer to help stock the park.
Another survivor is a drinking trough for the deer, which was cut into the rock, being filled with rainwater channelled from a natural outcrop.
Such a prominent feature as Rothley Crags were a natural choice for a defended settlement and there are the remains of a prehistoric hilltop enclosure. Sir Walter thought along the same lines and in the 1740s Garrett produced a design for the mock Rothley Castle.
It would have been both an eye-catcher for estate visitors and travellers, and a venue for excursions for Sir Walter's guests.
The castle, which still sits today on top of the crags, includes a central stone tower, with walls running to the north and south to join flanking towers.
Originally, there were battlements, while some of the cruciform slits can still be seen.
Stone figures, brought to Wallington from the demolition of Bishopgate and Aldersgate in London - including the griffins' heads now in front of the house - were used to embellish the castle, along with a whale's jawbone which was fixed to the walls.
A stone staircase in the castle tower led to a platform so allow visitors to enjoy the views.
The crags had previously been used for more serious purposes. The inner part of the prehistoric enclosure had been pressed into service as a defendable area to protect livestock from raiding Reivers.
Rothley Crags were also part of a chain of beacons to give warning of impending attack from the north.
The land is crossed by medieval boundaries from the days when it was a grange attached to Newminster Abbey in the Wansbeck Valley.
There is the possibility that the castle may not have simply been a folly and conversation piece. In 1745 the Jacobites had invaded and Rothley could have served a defensive role if necessary.
Whatever, Sir Walter was not finished and in 1769 the astronomer Thomas Wright of Durham delivered a design for Codger Fort, a mile north of Rothley, on a craggy outcrop overlooking Rothley Lakes. The stone, triangular bastion looks down on the road to Rothbury. Apparently, six cannon were obtained from Chatham Dockyard and installed at the fort.
Rothley Castle was still making a big impression in 1888, when the writer Tomlinson wrote: "Rothley Crags, a bold range of rocks, are covered in a profusion of heather and bracken.
"From the Rothley road there is a fine view of these broad and rugged escarpments, with huge boulders at their feet."
In 1879, the land was sold and remained in private hands until two years ago. The National Trust was able to buy the Grade Two-star listed castle and 242 acres, backed by a generous bequest from supporter Ann Dawson, who had stipulated that the money had to be used to buy land or property in Northumberland. The acquisition included half of the original deer park.
The formal woodland plantations are of exactly the same form as is shown on a map of 1777.
Harry Beamish, National Trust regional archaeologist, says: "Rothley Castle was about 18th Century fun and games, and it would also have given views to the coast and of the estate which Sir Walter was improving.
"It was a huge undertaking, but it was seen as a duty to take unproductive land and improve it. As well as the economic side of the development, having a deer park would have been seen as a mark of status.
"There was a mania for landscaping and if you had the resources it would have been quite fun.
"Taking a romantic setting and building the castle in it was improving on nature. The castle was intended to be seen from afar and for people to stop and comment on it."
More than 250 years later, they still do.