Head north along the A7 today, from Carlisle through Longtown, across the River Esk and over the border into Scotland, and it seems peaceful enough today, with no signs of its lawless past.

It’s only once you pass Canonbie that a concrete reminder of the Reivers emerges from among the trees – the solid, stern-looking Gilnockie Tower.

The sandstone and limestone structure is thought to have been built in 1519 or 1520. So if it’s not exactly half a millennium old it soon will be.

And it’s one of the finest examples of a 16th century pele tower still standing.

After the Reiver era, Gilnockie Tower became a ruin. Then 40 years ago it was turned into a house. It later fell back into disrepair.

“The timber had deteriorated to the point that it was in desperate need of attention,” recalls project manager Ian Martin.

But during the last four years it has been extensively repaired and re-opened to visitors – and restored to how it may have looked 500 years ago.

The work is not quite finished but Ian adds: “We are just fine-tuning now.”

And with its stone walls, wooden floors, large heavy doors, open fireplaces and spiral staircase it is certainly atmospheric, and an ideal setting for a museum of Reiver heritage and the history of the Armstrong clan.

The tower’s very first resident is thought to have been Johnnie Armstrong, a notorious Reiver who was hanged along with 36 of his men by King James V of Scotland.

Thanks to a folk ballad and the writings of Sir Walter Scott, he is probably the most well known of all the Border Reivers.

He operated a very lucrative protection racket that stretched as far as the River Tyne.

James V invited the leaders of the reiving clans to meet him, promising that if they were prepared to submit to him their lives would be spared.

So he set off north for the royal audience, dressed in his best attire, with an entourage of other Reivers including Elliots, Littles and Irvines.

But en route they were ambushed by a detachment of the king’s horsemen who escorted them to Caerlanrig. And it was clear that the king had no intention of sparing them.

We can’t know for sure whether Johnnie Armstrong lived there. But portraits of him all show the tower in the background. One of them hangs in the entrance today.

Astronaut Neil Armstrong – probably the wold’s most famous Armstrong – came to see the tower in March 1972 when he visited Langholm, three years after he’d visited the moon.

A section of the exhibition area on the third floor is dedicated to him.

James V’s successor James VI, who was also to become King James I of England, tried to solve the Reiver question by expelling many of them, including the troublesome Armstrongs. Many ended up in Ireland and America.

From there they also spread to Australia and New Zealand and visitors today come from all those countries. With direct flights to Carlisle from Dublin and Belfast he hopes numbers of Irish visitors will increase.

And then there are the Armstrongs from Chile.

“The story goes that there was an Armstrong who was captain of one of the tea clippers,” Ian relates.

“On his way back to Britain he stopped off in Chile, and met the love of his life.

“He stayed there and had a family. So there is a large contingent of Armstrongs in Chile. We’ve had some of them.”

A spiral staircase leads to the roof of the tower, offering impressive views over the surrounding countryside. Directly beneath are fields of noisily bleating sheep while the Scottish hills rise in the distance.

One admirer of the view, in 1943, was a Galloway bullock who managed to make his way up the spiral staircase and onto the roof.

“They couldn’t do anything to bring him down. So he was swiftly and humanely despatched.”

Over the edge? Ian nods. “He was on the menu that night.”

Ian, 72, was originally an electrical engineer but had always had a passion for history, and after retiring due to ill health he took a degree in Scottish and European history at Glasgow University.

So he provides a knowledgeable guided tour of the building.

There are five storeys to the tower. The ground floor is now the reception area and shop while the first floor houses the great hall.

It is furnished with chairs of different shapes, styles, sizes and colours, just as it would have done in the Reiver era.

Their habit was to steal different bits and pieces from different properties in the course of their reiving, and so create an interesting contrast of styles in their own homes.

Water running down the walls had done a lot of damage to the hall and fixing it was a complicated and laborious job.

“We had to cut away some of the stonework and find out how far the wet rot had progressed.”

The wooden joints were replaced with one from a former textile factory in Yorkshire.

The master bedroom is on the second floor and comes complete with 16th century en-suite toilet – a hole in one corner.

“That would have been something grand in those days.”

The plan is to put an old-fashioned loom in the bedroom to reflect the work of the woman of the house.

Artefacts, documents and other memorabilia of the Reivers and the Armstrongs will go on the next floor.

“This room will be more or less our museum,” Ian says.

“It’s where we have school groups, Women’s Institutes and others.”

Above one part of room is the famous quote from the world’s most famous Armstrong: “One small step for a man.”

It commemorates Neil Armstrong with letters, cuttings, photographs and other items and a print of a foostep made by his moon boot – one of those small steps that were, in his words, also “a giant leap for mankind”.

There are also garments made from lunar tartan, the pattern especially designed for him by Ian Maxwell of Eskvalley Knitwear of Langholm.

It contains black, brown and grey, representing the colour of lunar rock, and red for the rocket flame.

The 50th anniversary of the moon landing has reawakened interest in Neil Armstrong’s feat.

“We need to try and make the most of that,” Ian says.

The top floor is used for storage at the moment but he points out: “We are going to convert it into a conference room. We believe there is a market out there for a venue for small meetings.”

And from there a few steps lead to the roof, where it is possible to look out on all four sides.

Gilnockie Tower has already hosted a wedding with a historical theme. The couple were both history re-enactors – so they and their guests wore 16th century costume. More weddings are expected.

Surprisingly, no lottery funds or Scottish government money were forthcoming to pay for the repairs to the tower, and it has all been funded by its private owners. But Ian points out that the work may have been completed more quickly as a result.

“If we had gone that way there would have been committees, forms to fill in, all kinds of bureaucracy. We were able to get on with it.”

Johnnie Armstrong would surely be impressed with the results.

n Gilnockie Tower is open from 10am to 4pm every day until the end of October and from 11am to 3pm afterwards.

Admission costs £6 for adults, £5 for over 60s and £3 for children and students.

To book a guided tour, phone 013873 71373 or 07733 065587.