
Zaister |
You can find information on the Cinderlands in Pathfinder Adventure Path #10, "A History of Ashes", which, incidentally, is on sale right now.
You can go up the Storval Stairs, or ascend through Kaer Maga, or, if you're feeling adventurous, climb the cliff!

jhpace1 |

The Storval Stairs can be found in Rise of the Runelords: Fortress of the Stone Giants. There is also a Pathfinder Society game module called "King of the Storval Stairs" that expounds on the monument, I believe.
The Cinderlands are a raised continental shelf desert, the opposite of the American continental shelf off of the east coast. That's how I described it to my players at the table while we run Fortress of the Stone Giants. It goes up 1,000 feet, and only two places I know of that you can enter are the Storval Stairs and Kaer Maga. You might be able to go via Turtleback Ferry and Skull's Crossing, from the Rise of the Runelords, The Hook Mountain Massacre book. D2: The Seven Swords of Sin module has info on Kaer Maga.