The 3.1 mile-long plan to stop Harry Potter tourists trespassing at Glenfinnan Viaduct

It is a tourist attraction that is synonymous with Harry Potter and draws 500,000 visitors every year to witness it.

Now, transport chiefs are taking steps to protect the Glenfinnan Viaduct from trespassers, with a new measure intended to protect the railway while also being "sympathetic" to what is a scenic area.

The Glenfinnan Viaduct | AFP via Getty Images

A total of £500,000 will be spent on installing more than three miles of lineside fencing near the iconic viaduct.

Network Rail is managing the project, which will replace existing boundary fencing in need of repair. The fencing itself separates the track from public areas. Works will start later this month.

Network Rail scheme project manager Hayley Simpson said: “The investment we are making in renewing the fencing in Glenfinnan will help secure the railway and keep the public safe as they enjoy the world-famous views of the viaduct and surrounding scenery.

“The work will be delivered without disrupting train services and the fencing we will install will be sympathetic to the natural landscape through which the line runs and not affect people’s enjoyment of the many walking trails and the spectacular views.”

The viaduct's popularity among Harry Potter fans has increased the risk of trespass issues involving those attempting to take photographs of the scenery and passing trains.

The railway network operator has said the public’s view of the viaduct will be improved by tree and vegetation management, which will be required to clear space for the new boundary fencing.

Network Rail has said repairs to the iconic viaduct will not disrupt rail services and will not change the structure’s distinctive appearance.

It was announced in April that total repairs costing £3.4 million would be carried out at the viaduct.

Engineers are assessing the strength of the viaduct, while carrying out work to protect it from water erosion, and are due to complete concrete repairs and make improvements beneath the track.

The work on the viaduct, which is known globally for featuring in the Harry Potter films, will take just under a year to complete.

Glenfinnan, famous for its links to Bonnie Prince Charlie and the 1745 Jacobite Rebellion, has long been popular with sightseers. But numbers have risen tenfold since the Harry Potter films first came out in the early 2000s and have now reached around half a million each year.

A three-year travel management plan was put forward earlier this year, with a host of measures aimed at alleviating the pressure. They include number-plate recognition cameras to identify vehicles, extra parking for coaches, and the introduction of double-yellow lines in hot-spots.