They come silently out of the desert – a herd of camels padding across the sand, snaking in single file through the darkness. The first lifts its head, sniffing at the smoke of our bonfire and burning frankincense. Then, just as quietly as they had arrived, they all move off, until there is nothing but us, the endless dunes of the Empty Quarter and a glittering vault of stars.
I am into my seventh day of a "grand tour" of the sultanate – an ambitious 10-day adventure, careering the length of this remarkable country, taking in mountains, canyons, lush oases, beaches and desert, available as a new group tour with Wild Frontiers.
The journey begins in Muscat, the capital. From here we follow the Batinah coast west to Wadi Bani Awf and the al-Hajar mountains, the towering gateway to Oman's interior. A silent testimony to a time of geological chaos and immense volcanic activity, the range soars dramatically from a gravel plain. Climbing precipitous tracks, our 4x4s head into a wild rockscape of giant ophiolite rocks, limestone and splintering mudstone. We head towards Snake Canyon and the Wadi Nakhar gorge. Goats graze precariously on the rock face, feeding on clumps of acacia, wild olive, aloe and grasses. These isolated mountains and wadis – river beds – are also home to wolves, foxes, jerboas and gazelle.
After hours of nerve-racking driving, we reach the lofty canyon rim. Ahead of us is Jebel Shams – the mountain of the sun. At more than 3,000m above sea level, the peak is one of the highest on the eastern Arabian Peninsula. A vulture circles silently above the chasm. We teeter on the edge, gazing at this vast panorama known as Arabia's "grand canyon".
Beside me, a retired geologist examines the rock under our feet. "Jurassic coral," she says, smiling, and points to delicate shapes in the surface. "Millions of years ago, all this was ocean floor."
Two female shepherds emerge from a tiny shack pitched nearby and gesture to us. They show us their hand-made crafts: colourful bracelets, and mountain sandals woven from goat hair. After a night in tents in an eco- retreat – the only luxury of this trip – we set out toward the oasis city of Nizwa. En route, we visit Jabrin castle, with its exquisite painted wooden ceilings and 100-year-old tamarisk tree, and pick our way through the eerie ruins of Tanuf.
During the Jebel Akhdar war of 1954-7, the town was bombed by the RAF at the request of Said bin Taimur, the sultan, in an attempt to destroy the dissident Beni Riyam tribe.
This crumbling ghost town and the nearby forts of Nakhal, Bahla and Nizwa are reminders that this peaceful country was once dominated by conflict. Formerly the capital, the mountain-ringed city of Nizwa remains the key settlement of the interior; a fort with a colossal defence tower lies at its heart. The stronghold was built to protect its wealth, and its position at the crossroads of vital caravan routes linking the interior with the frankincense-producing region of Dhofar in the south, and the port of Muscat to the north-east.
Next we journey to the bustling market town of Sinaw. Men wearing white ankle-length dishdashas stand in the dust, haggling over the price of cattle, goats and camels that are being traded from the back of pickup trucks. Two Bedouin women wearing colourful robes and black burqas walk past carrying plastic shopping bags and babies with kohl-ringed eyes and yellow henna paste on their faces.
Traditionally Bedouin tribes from the coast would travel to Sinaw during the monsoon season to trade dried shark, before returning with their caravans laden with dates. Although we are here early for the market, there are already several Bedouin women in the square, selling balls of kohl with small decorative silver containers, henna, incense and burqas – a different design for each tribe.
Further east in Bidiya we fill the 4x4s with fuel and water, and let the tyres down before entering the desert. (Flat tyres give a better grip for driving on sand.) In the distance the yellow-ochre dunes of the Wahiba Sands line the horizon. Sand edges onto the forecourt, and a big yellow arrow points straight past a lone barber's shop into the wilderness.
The 12,400 square kilometres of the Wahiba run south from the eastern Hajars to the Arabian Sea and are home to isolated settlements of semi-nomadic Bedouin. We speed past one or two of these camps, where camels are kept in makeshift pens.
Up and down, to left and right, tracks come and go, but our driver and guide Ahmed knows these strange billowing sands well. Those taking self-drive tours often get into trouble here, he tells me. "If you are following the tracks of another vehicle and the tracks disappear, stop immediately." He points to a large patch of sand that looks identical to the kind we are crossing. "See there, quicksand. It's younger and paler than other sand." I can't see any difference.
For hours we plough on. We pass a Bedouin woman with her goats, miles from any obvious shelter. We give her a bottle of cold water and move on. The sand begins to look fluid and the light grows hazy from the sand particles in the atmosphere.
After a hard day's drive we see a different horizon: a clear blue line – the Arabian Sea. Pausing by a vast sand basin, scarred by the tracks of dare-devil drivers racing their 4x4s into its depths, we set up camp. From now on this is wild camping. As our drivers prepare a simple meal of curry and rice, a bottle of duty-free booze is discreetly passed around. With a shortage of tonic, gin is mixed with lemonade or sweet mango juice and drunk from tin cups. Our pudding is halwa, a gelatinous, sickly-sweet confection made with dates, saffron, cardamom, almonds and rosewater.
Back on the road, we drive south, hugging the coast, this time on modern asphalt. Forty years ago there was only 15km of tarmac in Oman; now new roads criss-cross the country.
"Before 1970 we were in the dark," Ahmed tells me. "Sultan Qaboos changed all that."
The Omanis are fiercely loyal to their leader. A recent article in the Oman Daily Observer talks of "the blessed era under the wise leadership of His Majesty Sultan Qaboos".
Surely that's a bit over the top, I say. Well-informed Ahmed shakes his head and talks to me at length about his country's past and future. "When Sultan Qaboos came to power, there were just two schools in the whole country, life expectancy for women was just 42, with 90% dying from childbirth. There were no hospitals. Now we have excellent free healthcare, 1,280 schools and a strong economy. You would be crazy to think things haven't improved."
He tells me that every year the sultan travels the country with large camps so that people from rural areas can visit him and ask for help: "I guess that there are few places in the world where you can tell your leader face to face you want electricity, and have pylons delivered three days later."
Herds of goats and camels lazily cross the roads with their young, oblivious to speeding traffic. We see mangroves, glimpse flamingos and pass vast salt flats. At Khaluf we encounter beaches tinged pink from millions of tiny shells, then drive for miles over white beaches, some layered with rubbish washed up from the sea, and past fishing settlements where boats and pick-up trucks are covered in seaweed.
The following morning, the tracks around our remote beach camp show this is a place teeming with wildlife – foxes, snakes, lizards and perhaps even hyena. The sea, too, is brimming with life. A school of dolphins pass us, cresting lazily out of a glassy sea. There are at least 13 species of whale and dolphin in Omani waters. Five endangered species of turtles can also be found here, and are protected by royal decree.
We turn again to the interior, towards the Empty Quarter. The Rub al Khali, in Arabic, is another vast expanse of sand, covering about 650,000 square kilometres of the Arabian peninsula – an area about the size of France. This is the heartland of the nomadic Bedouin, and the setting for Wilfred Thesiger's classic book Arabian Sands.
At first, I see only a grey wasteland, an endless gravel plain interspersed with "nodding donkeys", a sign of the oil production that makes Oman comfortably independent. The tracks are rough and in the space of an hour we suffer two punctures. Strewn on either side are abandoned tyres. It is hot, 38C , and we are entering wild territory.
Suddenly, rising out of nothing, the dunes appear. Rust-red and magnificent, they beckon us. The track disappears. Minutes later, we are in another world.
I pitch my tent and walk out in the warm evening air. Littered between the dunes are strange round rocks, which look like small, petrified cauliflowers: geodes. Crack them open and you will find crystals within. Later, the camels come. There is excitement in the air that night.
Around the bonfire, with most of the group tucked up in their sleeping bags, the drivers play music on their iPhones, and dance. The tour guide, Dhala, and I contemplate sleeping out under the stars, but with a brisk, sandy wind developing, we decide against it. A good job too, as a poisonous camel spider was found walking across the chest of Suleman, one of our drivers, the following morning.
Before dawn, I start up the nearest dune along with Dhala. At the top we sit a while, looking out over a rolling expanse, watching the sun rise. It's like being on top of the world. The wind picks up. Fine red sand streams over the ridges and in no time we are covered. Seeing busy activity below, we stagger back to camp like drunkards, sinking knee-deep into rippled dunes.
The searing heat and hard wind soon make for uncomfortable travelling. Every so often, one of the 4x4s gets stuck in the sand, and we all climb out, pushing, digging or watching impotently as the drivers use ingenuity to escape.
We tie turbans around our faces and breathe shallowly. Sand stings any exposed skin. Lunch is taken under a tarpaulin strung between the vehicles. Sand devils spiral in the distance. Ahmed checks the weather report, and advises us to move on. With regret, we retreat from the Empty Quarter.
We drive through the desolate Moon mountains, and plunge down spectacular hairpin bends towards the city of Salalah, and our first shower in five days. We pass banana, papaya, mango and coconut groves, and acres of frankincense trees. Small thatched fruit stalls line the road. A beach-seller walks along a promenade selling pink candy floss. Men in dishdashas sit in groups, playing the ancient game of hawalis with shells in the sand.
Salalah has a unique monsoon climate. Between June and September, the rains transform the surrounding area into a veritable Garden of Eden. Despite the weather being humid, wet and hot, thousands of people descend on the city and surrounding oasis. The air, Ahmed tells me, becomes thick with fog and smoke from the burning frankincense and barbecues of picnicking Omanis.
We are at journey's end. We have covered about 2,500km in 10 days and, though exhausted and grubby, we have encountered some of Oman's most remarkable natural and historic treasures. Those wanting a few days of luxury or relaxation, however, should perhaps upgrade their hotel and stay on in Salalah, or book in to the Chedi in Muscat.
As the moon rises over the Arabian sea for the last time on this tour, I leave our group and walk alone down to the beach. Ahead of me a lone grey heron stands motionless, silhouetted against the gently lapping waves. I remember that the joy of travelling is as much the thrill of new adventures as it is the chance to be still for a moment.
• The Oman Desert Adventure with Wild Frontiers (020-7736 3968, wildfrontiers.co.uk) costs from £1,895pp. This includes local transport, meals, accommodation in one or two-person dome tents, two- and three-star hotels at the beginning and the end of the tour and the services of a guide, but not flights. The next scheduled tour begins 1 November. Oman Air (0844 482 2309, omanair.com) flies from Heathrow to Muscat direct from £518 return, including taxes
