by : Bethan McKernan in Shibam, Yemen

On the edge of the vast Empty Quarter desert that dominates the Arabian peninsula, white and brown towers rise together out of the valley floor like tall sandcastles. Once they welcomed weary caravans traversing the Silk Roads: now they stand as testimony to the ingenuity of a lost civilisation.

This is the ancient walled city of Shibam, nicknamed the “Manhattan of the desert” by the British explorer Freya Stark in the 1930s, in modern-day Yemen, a country also home to an untold number of other archeological treasures. The kingdom of Saba, ruled by the legendary Queen of Sheba, and many other dynasties of the ancient world rose and fell here, their fortunes linked to Yemen’s position at the crossroads of early frankincense and spice trades between Africa and Asia.

Today, as a result of Yemen’s complex civil war – now in its fifth year – many of the country’s wonders have been damaged or are under threat. While the destruction pales in comparison to the human cost of the conflict, the country’s rich cultural heritage has also been ravaged.

At least 712 mosques and 206 archeological sites have been affected since the war broke out in 2015, according to the Legal Centre for Rights and Development in Sana’a. The true figures are believed to be much higher: deliberate targeting by Saudi airstrikes, Houthi rebels, Islamic State and al-Qaida, and a booming smuggling trade have all contributed to the loss of thousands of relics.

Shibam, a 1,700-year-old settlement in the valley of Hadramawt, has largely escaped direct violence, but is still suffering from years of neglect, despite being a Unesco world heritage site.

Named for King Shibam Bin Harith Ibn Saba, it is one of the oldest – and still one of the best – examples of vertical construction in the world. In the 16th century, Shibam’s inhabitants found they had run out of space to expand. To compensate, they began to build carefully on a rectangular street grid, and instead of spreading out, they built up, giving the world its first skyscrapers. The tallest of Shibam’s mudbrick and cedarwood towers contains eight storeys and stands 30 metres high.

High above the desert valley floor, Shibam is close to water sources but relatively safe from flooding. The shadows cast by the tall buildings provide lots of shade to the hot streets below and the fortified outer wall and high vantage point from the towers made it hard for rival tribes to attack.

The city’s 3,000 residents still largely follow the traditional living pattern, with in some cases up to 40 family members in the same tower. Animals and tools are kept on the ground floor and food is stored on the second. Elderly people live on the third and the fourth is used for entertaining. Higher levels are occupied by more nimble families, with childless newlyweds on the roof.

Internal doors link up to 10 houses on a street block, although bridges from roof to roof that saved elderly legs from climbing up and down staircases have not survived.

Today the streets are too narrow for cars, but Shibam is largely self-sustaining: its farmers and shopkeepers cater to the small population and many men are employed baking the straw and mud bricks used in construction. As in many Yemeni cities, goats and chickens roam the streets.

“Lots of young people have left,” said Ali Abdullah, 28, who was looking after his family’s goats along with his 10-year-old brother, Majid. “Shibam is beautiful but there is no reliable money to make here unless they start preserving the buildings again.”

While their owners do what they can to rebuild crumbling walls and protect their homes from termites with limewash, Shibam’s 444 buildings are vulnerable to wind, rain and heat erosion: the outer layers of clay need constant maintenance to stop the walls cracking and eventually collapsing.

Since Yemen’s Arab Spring revolt in 2011, funding to help preserve the city has dried up, as has the once steady flow of tourists, said Salim Rubiyah, the head of the local association responsible for looking after the public buildings inside Shibam’s walls.

Two towers have collapsed in the last few years, and at least 15 more are in urgent need of repair, according to the General Organisation for the Preservation of Historic Cities in Yemen.

“Shibam is very special,” said Rubiyah. “I don’t know why everyone doesn’t build like this. I worry that this will be the last generation who are able to make a life here and appreciate the city’s beauty.”

Elsewhere in Yemen, the story repeats itself. A ruin reputed to be the location of the Queen of Sheba’s throne, potentially the only vestige from her 10th-century BCE kingdom, lies in the desert near the Yemeni town of Marib. As the purported political, religious and economic centre of her legendary civilisation, the site is considered of huge significance. Prof Abdullah Abu al-Ghaith of Sana’a University has described it as the eighth wonder of the world.