Petra was carved from solid rock in the 5th and 6th centuries BC and was the capital of the Nabatean Arabs. Visit in the evening for the most atmospheric experience and walk through the beautiful Siq passageway to view the awe-inspiring Al Khazneh (the Treasury), which at night is lit by hundreds of candles. But be sure to go back during the day to see the rest of the city in all its glory under the fiery desire sun.