As mentioned, there are two main thaniyas, or siqs into Petra. There is also a third, much less know thaniya, that is a great experience. However, this is quite a scamble and should only be done by those who are in good shape and with good footware. Also, it is an active water path, but is dry most of the year. However, it should not be attempted from October to March, unless you are certain that it will not rain anywhere in Jordan. Water can collect, miles away, and then rush down these dry waterways. There is enough water to toss tree trunks and great rocks along, and these must be climbed over in the dry time.
The small siq does not actually enter the city but goes through the mountain farther on. This siq is not the second “thaniya” into Petra as it does not enter the city proper. The second thaniya exits Petra from the far end of the colonnade Street and descends down to Wadi Araba.
This siq is not designed for the casual tourists. It has places where visitors will have to climb rocks and clamber over obstacles that the water has deposited.
If you are not agile, DO NOT TAKE THIS ROUTE. If there is ANY THREAT OF RAIN WITHIN FIFTY KILOMETERS, DO NOT TAKE THIS ROUTE.
It is not uncommon for this wadi to fill with water during the time between October and April. It may rain thirty to fifty kilometers away, and the water will rush down the wadi, and will create a flash flood. If you are caught in the far end of the wadi during a flash flood, you would be crushed to pieces by the rocks and water. Please heed this warning. Otherwise, this siq offers some of the most spectacular scenery in Petra, and is well worth the effort.
The path to this siq travels through the water tunnel, and then follows the wadi along. You will need to turning left through a crack in the rock. If it narrows to nothing, then you need to back out and try the next one. It will eventually come through the siq and out into the Petra Valley near the Christian Tombs. This siq will end in what Dan Gibson has called The Cave of Muhammad. However, it is easier to reach this spot by entering from the Petra side.