After a quick breakfast at the Marriott we jumped in the car and headed to Wadi Musa. The drive only took ~10 minutes, and we didn’t have any issue finding street parking across from the Movenpick.
To give you a sense of how the town and the historical site are oriented, here’s a picture taken from a hill above Petra, which I’ve added labels to.
It’s about 2 kilometers from the Petra Visitor’s Center to the Treasury, to give you a sense of the distances. The Treasury itself is only about halfway down the main road into Petra — you’ll go another 2 kilometers to the end of the main road where you can see some of the other key sites.
You’re looking at a minimum of 5 miles of walking if you stay on the main road and don’t explore any of the side trails, so keep that in mind when choosing your footwear!