Tiiren is the highest mountain at least in the Spine of Sirdanth, and possibly on all of Avishraa. It is a largely north-south ridge sited in the approximate middle of its range.
The headwaters of the Dhirim flow from its eastern slopes, but because the river curves counterclockwise nearly 180° around the mountain and its lesser companions before continuing northwest toward the Crimson Sea, it has tributaries on the northern and western slopes as well. Two of its neighboring mountains, with which it cradles the uppermost Dhirim valley and the Citadel which occupies it, are Oghyina to the northeast and the volcano Vana Idrizal to the southeast.