Petra, the city the Nabataeans cut from the cliff

Most famous ancient cities were built up from the ground, a block at a time. Petra was cut down into the cliff. Its best-known façades were carved from the top downwards, out of the soft, banded sandstone of southern Jordan, by masons who couldn't correct a mistake by swapping out a block. What survives is less a ruined city than a great deal of decoration with very little behind it. Most of the grand fronts open onto plain, square rooms cut into the rock, and the houses, markets and streets that once filled the valley floor have largely gone.

The people who did the carving were the Nabataeans, an Arab people who grew rich on the caravan trade in incense, spices and other goods moving between southern Arabia and the Mediterranean. They didn't leave much history of their own, and much of what we know comes from Greek and Roman writers and from the city itself. Petra was their capital by the last centuries before Christ, and at its height in the first century AD it was a crossroads that knew exactly what it was worth.

A city with a narrow front door

The usual way in is still the original one: the Siq, a winding cleft in the rock a little over a kilometre long, in places only a few metres wide, with walls rising far above it. It was a natural defence, and the Nabataeans also used it as a water engineer would. Channels cut into the rock along its sides carried water towards the city, part of a system of dams, cisterns and conduits that let a desert capital support a sizeable population and a few gardens besides. The sandstone gets the attention, but the water engineering is what made Petra possible.

The Siq also delivers the city's great piece of theatre. At its far end the cleft narrows, the light changes, and the façade of the Treasury, al-Khazneh, appears in the gap, salmon-pink and impossibly crisp after two thousand years. The name is a later invention, from a local story about pharaoh's gold hidden in the urn at the top, and the bullet marks on that urn are the work of people who believed it. It was almost certainly a royal tomb, often attributed to King Aretas IV, who reigned around the turn of the first century.

Beyond the Treasury

Many day visitors see the Treasury, walk a little further and turn back, which is a pity, because the valley opens out beyond it. There is the Street of Façades, a terrace of tombs in descending order of grandeur. The theatre was cut into the hillside and later enlarged under Roman rule. Then come the Royal Tombs, set high in the cliff, where the colour of the stone is at its most extraordinary, swirled in reds, ochres and greys like marbled endpapers. At the far end of the colonnaded street, the remains of temples and a market area give some idea of the city that once stood on the valley floor.

Then there is the Monastery, ad-Deir, reached by a long climb of several hundred rock-cut steps. It is larger than the Treasury and plainer. It gets far fewer visitors, because of the steps, and that is the best reason to go. It is worth starting early, both to beat the heat and to get there before the steps fill up.

Nearby, Siq al-Barid, often called Little Petra, is a smaller valley of the same carved façades. It is thought to have been a suburb where caravans were received, and it gives a useful sense of scale: the Nabataeans did not save their carving only for the capital.

Rome, an earthquake and a long silence

The Nabataean kingdom was absorbed into the Roman Empire in 106 AD, under Trajan, and Petra carried on as a provincial city. Trade routes shifted over the following centuries, and a severe earthquake in 363 damaged much of what had been built. The city faded slowly. Crusaders built a fort nearby in the twelfth century, and the castles at Shobak and Kerak, both on many itineraries, belong to that later chapter. For most of the following centuries, though, Petra was known mainly to the Bedouin who lived in and around it.

Europe heard of it again in 1812, when the Swiss traveller Johann Ludwig Burckhardt, travelling in disguise, talked his way in on the pretext of making a sacrifice at the tomb of Aaron on a nearby peak. He couldn't take notes openly, and he stayed only briefly. It was enough. Within a few decades, artists and travellers were coming to draw and describe the place. Petra was inscribed as a World Heritage Site in 1985.

How tours fit it in

A single day covers the main valley, but not comfortably. The tours that give Petra real time tend to pair it with Wadi Rum's desert, the mosaics at Madaba, the view from Mount Nebo, the Roman city at Jerash and a float in the Dead Sea. Explore Worldwide's Jordan Discovery, eight nights, takes in all of those as well as the castle at Kerak and the Red Sea at Aqaba.

Travelsphere's Jordan's Ancient Wonders, seven nights, adds Shobak and Siq al-Barid to Petra itself. Just You's Jordan, a Land of Ancient Treasures and Empires, also seven nights, covers much the same ground for travellers who would rather go solo in company.

Spring and autumn are the comfortable seasons: summer in the valley is hot and largely shadeless, and a winter day can be cold, with the occasional flash flood that the Nabataeans' dams were built to tame. Whenever you go, take good shoes and plenty of water, and leave enough time for the steps.