They look like towers from a fairy tale, rows of chocolate-coloured bricks held together with mud and straw, marked out by white gypsum and windows so intricate they seem entirely impractical. The ancient homes of Old Sana'a are a wonder of the world, unique to Yemen.
Standing by the last remaining of the seven great gates to the old city, Abdullah Lutf Zayed points across the square to the home he inherited from his grandmother, a four-storey building overlooking the souk that is one of the 7,500 minor miracles of architecture that make Old Sana'a an internationally protected heritage site.
"The ground floor is for the animals, or used to be," said Zayed, his patterned scarf folded neatly across his shoulders, his ceremonial dagger, the jambiya, tilted at a jaunty angle in his belt, befitting a man of notable means and family.
"The first floor is for family things, the second floor has the good rooms, for eating, receiving guests and weddings. The third floor is for sleeping, and the top floor, the mafraj, is for chewing." And that means khat, the bitter green leaf beloved of Yemenis for its mind-pleasing properties.
"The homes have passed down through history and generations, unaltered by modern things. Old Sana'a," concluded Zayed, "is protected by God".
That it may be, but the homes that stand witness to some 2,000 years of habitation in Old Sana'a are now in need of a little protection by man as well. Lack of time, money and care by locals fixing their homes, dithering by Unesco – the international organisation tasked with ensuring the continuance of building traditions in Old Sana'a – as well as local administration foul-ups and alleged corruption have conspired to threaten Yemen's unique architectural heritage like never before.
Serious threats to Yemen's internal stability have not helped. Just last week seven people were killed in a gunfight between tribesmen loyal to the government and fighters from the Houthi rebel group, the most serious violation of the February ceasefire that brought an end to the sixth round of war in north Yemen.
Last week a suicide bomber tied to the Yemen-based al-Qa'ida in the Arabian Peninsula, the group which claimed responsibility for the attempted bombing of a US airliner on Christmas Day, detonated his explosives as the convoy of Britain's ambassador to Sana'a drove past.
Yemen's acute political and economic instability – unemployment tops 40 per cent while rates of malnutrition are the third highest in the world – and the fight to contain al-Qa'ida have pushed heritage protection far down the list of priorities of a government struggling to maintain its rule. "We have 360 homes that have been evacuated because they are about to collapse," said a local council member, Abdel Khaliq al-Akwaa, as he sifted through pottery inscribed with Arabic and Hebrew recently discovered beneath the foundations of one Old Sana'a home.
"The water system is being destroyed and is threatening all of Old Sana'a. The majority of buildings in the city now have damp invading their foundations. We plan to save them, but we need help."
A shortage of the right kind of mud – a heavy clay mixed up with camel dung and straw – as well as the skilled craftsmen needed to apply it means many residents repairing homes in Old Sana'a are opting to use cement, new bricks and even concrete blocks to save on costs.
"It's time to ring the alarm," said Elena Dicapita, a professional restorer working on decorations inside Old Sana'a's Grand Mosque – at around 1,400 years old, thought to be the third oldest mosque in the world.
"Ernest Hemingway said Old Sana'a was the most beautiful city he had seen, but if we don't do anything now the result will be this," she said, pointing to the red bricks and cement of a new home being built close to the mosque, garish looking against the soft amber tones of the old buildings surrounding it.
When the damp began rising through the stones and old bricks of what is believed to have been the palace of Immam Nasser Mohamed Ibn al-Kassem, who ruled Sana'a nearly 800 years ago, the present resident Saleh Ghotheim called the water authority to report the leak.
That was in 2001. Today half the building is in pieces on the ground. What remains standing is a confusion of rubble and rooms patched back together, some with old bricks, some with new and with plenty of cement in between.
As we clamber up the floors of the former palace, its walls reveal a glorious past – the Seal of Solomon, reputed to give him power over the dreaded djinn, carved into white stone, intricate patterned windows of coloured glass – now cracked, faded and covered with dust. "In 2001 it would have cost one million rials (£3,200) to repair the house. Today, if I restore it in the right way with mud and old bricks it will cost me 70 to 80 million rials," said Ghotheim.
That cost is halved, he said, if they use cement and cheaper, thicker bricks. "We want to restore the house as the same historical place it once was. But we don't have the money and neither does the government. Why don't those international organisations who care about history come to help us?" Mr Akwaa is now pushing for the council to take over responsibility for Old Sana'a's buildings, saying it has secured a budget for restoration this year of around $8.5m (£5.6m), a rise of more than double that available in 2009.
Activists are urging the government to form a specialised committee of architects, scholars and experts to oversee the preservation of Yemen's national heritage and to press Yemen's wealthy Arab neighbours, as well as the West, to provide money to preserve Old Sana'a.
"Sana'a belongs to the world, to the history of beauty and taste, like Venice, like Bruges, Istanbul, Prague or Rome," said Marco Livadiotti, a life-long resident of Old Sana'a who has been involved in many restoration projects and recently established a company to raise awareness of the dangers facing the city.
"Oil is declining, water is running out and the sea is over-fished. But Yemen has one of the richest heritages in the world. If we save it, the country can grow wealthy just on the income from tourism."
But time, as Mr Akwaa knows, is running out. "Sana'a is part of an international human heritage. But it is also a living city, constantly in need of restoration. We can't wait years when people are repairing their homes every month."Reuse content