The Great Wall of China

In 2016, the then-presidential candidate Donald Trump made the extension of the USA Mexico border wall a major electoral promise. Four years later with just 80 miles added, the total length comes to 452 miles (727 km). The entire border stretches 1,954 miles (3,145 km) with further wall expansion unlikely.

In comparison, the Chinese built an estimated 13,170.70 miles (21,196.18 kilometres) of the Great Wall of China as announced by China's State Administration of Cultural Relics in 2012.

This may have been over many centuries, but must stand as one of the most spectacular engineering feats in recorded history, even if seeing it from space with the naked eye is actually a myth.

Since the 7th century BCE, the wall has taken a variety of routes and was originally constructed of impacted earth, with many assuming its main purpose to repel Mongol attacks. Although it was so much more, acting as a border to regulate immigration as well as allowing the imposement of import and export duties.

Locals often robbed the stone for local building projects

The impacted earth mound was encased in brick and stone during the Ming dynasty in the 14th - 16th century with signal and watchtowers built at regular intervals.

Every wall must have a start, with the Old Dragon's Head at Laolongtou some 180 miles east of Beijing seen as a start point where the Ming wall reaches the Bohai Sea.

The east gate adorned with the sign "The First Pass Under Heaven"

The 16-mile Shanhai pass bordered by the sea and the Yan mountains has always been of strategic importance with over 80,000 soldiers garrisoned in the area in times of tension.

The Ming "upgrade" to stone and brick was needed to protect from emerging technologies such as cannon. Ironically the overthrow of the Ming dynasty in 1644 was helped by the local commander switching allegiance and opening the gates so allowing the Machu to enter with no blood spilled. Human nature will always be the weak link.

The restored section on the other side of the pass shows how the design allowed for five horses or ten warriors line abreast to move swiftly while the raised battlements indicate which side faced the enemy territory. Smoke would be generated during the day or fire at night to alert neighbouring watchtowers if the enemy was spotted.

Heading further west, parts of the wall have been lost by the creation of the Panjikou reservoir, although the steepness and remoteness of terrain show how difficult it must have been to build. Chinese legends suggest thousands lost their lives in the construction with the most famous story centred on bodies being placed in the foundations, although no evidence has been found to support this practice.

Being off the beaten track, you really get a sense of rural China with the wall in a poor state of repair.

Once an important garrison, the wall climbs out of the reservoir at Xifengkou which roughly translates to "Happy Meeting". The rather curious local legend tells us about a son who sets off to help build the wall but failed to return the following winter. A worried father set off to search for him, fearing his death, and eventually found him here. However, they were so happy to see each other, they laughed themselves to death.

One of the watchtowers at the Luowenyou section

One of the most impressive sections is the Taipingzhai Great Wall being a 2152 metre section defending the Huangyaguan Pass using the Banlagang and Wangmaoding mountains as natural defences.

The renovations were overseen by Qi Jiguang, seen as a national hero in the 15th century for defeating Japanese pirates.

The Ji Garrison housed in Baugua castle was one of eleven garrisons created by the Ming dynasty with the layout having a maze-like quality. Having spent a night within its walls, I can vouch for the fact it's very easy to get disorientated!

Considered by many, the most beautiful stretch, the Jinshanling section is some 10.5 km in length made up of sixty-seven watchtowers and three beacon towers.

If you look carefully you can sometimes find the name of the brickyard

The start of the Simatai section

Gazing in one direction you can see the wall heading off to the Simatai section with its snake-like qualities hugging the top of the mountains.

Looking the other way, the Gubeikou section stretches to the horizon.

For many, their experience of the great wall will be a day trip from Beijing where restored stretches of the wall remodelled by the Ming dynasty can be found.

While others will say, why would you get excited about what is essentially just a wall? But if you fancy some fresh air, appreciate great scenery, want a chance to marvel at an engineering masterpiece, and can cope with the high number of steps, a week walking different sections of the Great Wall of China will not disappoint.

Watching the sunset over the Jinshanling section will always be one of those special travelling moments.