Information relevant to the 11th chapter of The Chosen
the Pillar of Heaven
The south-eastern depression of the Pillar of Heaven contains the Quyan Ladder.
The Pillar of Heaven is the remains of the last volcanic eruption at Osrakum. A vast cinder cone, eroded over aeons, leaving only the basaltic intrusion of the main vent. This structure actually consists of two pipes ‘welded’ together, that reach a height of 2500m above the level of the Skymere
This sketch shows my initial conception of the Pillar of Heaven that had a small lake set into its summit. This lake fed a series of waterfalls that cascaded down the Pillar, in what later became the Rainbow Stair. At this point I conceived of the Halls of Thunder as being built into the cliffs overlooking this lake. Both these and the summit lake were discarded
The final form the Pillar took is shown in the first diagram—and can also be seen in the model I made of Osrakum. It is based on Devil’s Tower in Wyoming— that, incidentally, was the mountain playing a central role in Close Encounters of the Third Kind.
The Pillar of Heaven, at the heart of the crater, dominates Osrakum. Close to its summit it has been hollowed to form the caves and chambers known as the Halls of Thunder. It is here that the God Emperor and the rest of the House of the Masks retire from the summer heat. In this respect, the Halls of Thunder perform the same function for the Imperial House as do the various eyries of the other Houses of the Chosen. The Halls of Thunder are reached from the Labyrinth by means of the Rainbow Stair
The Yden is the region lying within the Ydenrim—the lip of a submerged, ancient crater. This lip rises some little way above the level of the lake
Much of the Yden is land that is the result of the subsided ash cone of the volcano, of which the Pillar of Heaven is the only remains—that volcano’s main vent solidified into basalt. The rest of the Yden consists of shallow lagoons whose level the Ydenrim raises above that of the surrounding lake
The diagram shows the Labyrinth, built on the higher ground lying between the Pillar of Heaven and the Plain of Thrones. Around the base of the Pillar are the Forbidden Garden with its terraces. Dotted lines show height contours. Note the wide contour to the northwest (this is clearer on the expanded diagram) that shows the wetlands that slip away into the lagoons
Also shown is the route taken by Carnelian and Osidian on their first visit to the Yden: from the Quyan Stair, through the Forbidden Garden and down towards the lagoons