Palmyra is a ruined caravan city in the desert of central Syria, between Damascus and the Euphrates, where colonnades of honey-gold limestone still run for more than a kilometre through the sand, and it is the city that grew rich on the silk road, was ruled briefly by a queen who defied Rome, and lost its greatest temple to ISIS in 2015. The city rose where it did because of one spring: Efqa, warm and sulphurous, watered an oasis in the open desert, and for a thousand years the caravans between Persia and the Mediterranean stopped here to pay Palmyra's tolls; the spring ran dry in 1994, after four thousand years, emptied by drought and pumping. The wealth built the Great Colonnade, a street of 750 columns of which more than 200 still stand, framing the walk through the heart of the city toward the temples and the desert hills, past the theatre, the agora and the baths, and through the Monumental Arch, which marked the turn in the street until it too was blown up.
At the end of the colonnade stood the Temple of Bel, the largest religious building in the Roman Near East, dedicated in 32 AD and standing for nearly two thousand years until ISIS dynamited it in 2015; one gateway survives in a field of blocks. The same months killed Khaled al-Asaad, who had looked after Palmyra's antiquities for over forty years and, held captive, refused to reveal where the museum's treasures had been hidden. West of the city dozens of tower tombs stand in the Valley of the Tombs, each several storeys high, where the merchant families laid their dead in carved niches, and above them the Arab citadel on its hill looks down on the whole ruin at sunset, when the columns go orange. Zenobia ruled from here in the 270s, took Egypt and Anatolia from Rome, and was led through Rome in chains. Palmyra is a city that the desert, the empire and the war have each tried to erase, and the columns are still standing in a row.