Ceiling: 30 feet high.
Illumination: The City of Brass is brightly lit day and night.
Rubble These areas of loose scree are difficult terrain. A creature that runs, charges, or makes a double move through rubble must make a DC 20 Acrobatics check or fall prone.
Fire Pool: The shrine of Imix at the heart of the Eternal Flame Pavilion is surrounded by onyx-walled pools of pure elemental fire. The largest of these pools is the center of Tiamat’s corrupt rituals and is pro- tected by a dome of magical force. The only entrance into the fire pool is by way of the firefall that descends into the fire whirlpool (see below).
The roiling elemental fire of the pool is interrupted by a series of onyx pillars (see below). Any creature that starts its turn in the air above the fire pool must make a DC 28 Endurance check (a free action) or take 3d8+10 fire damage. Any creature that enters or starts its turn within the fire pool takes 4d8+10 fire damage. The protective dome of magical force that surrounds the fire pool blocks movement, line of effect, and magic (including teleportation effects). Creatures can enter the fire pool only by way of the smaller whirlpool and the firefall; see below.
Onyx Pillar Rough-topped pillars of magical onyx thrust up 5 feet above the roiling surface of
the fire pool, including one large pillar that is the centerpiece of Tiamat’s rituals. A creature standing on an onyx pillar is partially protected from the crip- pling heat of the fire pool. Any creature that starts its turn on or above an onyx pillar must make a DC 28 Endurance check (a free action) or take 2d8 + 5 fire damage.
Firefall Raw elemental fire surges like a waterfall down from the fire pool. The firefall is the only access from the open whirlpool to the warded fire pool. The 20-foot-high firefall can be ascended by flying or with a DC 33 Athletics check. A creature that flies up the firefall takes 3d8 + 10 fire damage. A creature that ascends the firefall with an Athletics check takes 4d8 + 10 fire damage.
Fire Whirlpool: Where the flow of fire courses down from the larger fire pool, it creates an elemental vortex. The smooth onyx walls of the whirlpool are 10 feet high and can be climbed with a DC 20 Athletics check. A creature that ends its turn on the onyx wall takes 2d6 + 8 fire damage.
Any creature that enters or starts its turn in the whirlpool takes 3d8 + 10 fire damage and is dazed until the start of its next turn. A creature that moves 1 square into the whirlpool must make a DC 19 Acro- batics or Athletics check (a standard action) to grab the edge and clamber onto the wall. A creature that fails its check or moves more than 1 square into the whirlpool is caught up  in the vortex. A creature must make a DC 28 Acrobatics or Athletics check (a standard action) to escape the vortex. One creature on the wall can aid this check. On a creature’s third failed check to escape the vortex, it is pulled down within the elemental maelstrom and irrevocably destroyed.