The Pinnacles Sublime is a demiplane of mountain ranges that inverts the expected behaviour of temperature. The sky above the mountains is dominated by a gigantic, low-hanging red sun that scorches the tips of the peaks, melting the rock into magma flows. As one descends the mountains, however, the temperature drops dramatically, giving way to a frozen landscape of glaciers and pine trees on the lower slopes. The demiplane was given its name by The Couriers (Orien Expedition No.2), and was known previously to the Kastar Ghaash'kala as the Frostfire Mountains.
The environment of the Pinnacles Sublime is extreme, containing dangerous temperatures on both ends of the spectrums within relatively short distances from each other. Heat exhaustion, and freezing, are constant concerns, and the mountainous terrain presents its own hazards and challenges. The temperature at the lowest point is a pleasant -120°C, which rises by about 30°C for every 1000ft increase in altitude up to the peaks at 15,000ft, which average 330°C.
The upper altitudes are a volcanic hellscape, and mainly populated by fire elementals. Little else can actually survive the temperature, or the scalding steam that rises from the rapidly cooling magma as it descends the mountain slopes, forming the demiplanes only clouds.
Lower altitudes are more populated. There is a relatively narrow band of green on the slopes between 5000ft and 6000ft, where the temperature is relatively comfortable, 0°C at its lowest point and 30°C at its highest. This strip of land on the mountains is home to a vast boreal forest of pine trees. At the bottom edge of this band, the forest descends into ice and snow, with the trees becoming sparse and stunted before giving way to tundra populated by herds of mammoth, and the equally large predators that feed on them, with a sheet of ice and snow below that.