The Smoking Pit

The smoking pit is a partially active caldera of a volcano. The caldera sits about halfway up the Little Sister and constantly fills with a heavy smoke which undulates within the lips of the caldera, like a roiling black and grey soup that has been loosed from the bonds of gravity, but is uncertain if it wishes to leave the bowl in which it is served.
The caldera is said to have been visited often by an ancient mage for its magical properties. Scholars today theorize that this ancient mage was Prelore, the Wizard King, based on the legends about the caldera that now exist in folklore. The caldera's smoke is comprised of a toxic blend of volcanic gasses. A person can endure the toxic gasses for a handful of minutes only before falling unconscious and eventually being poisoned to death. However, it is said that the dense gas that floats beneath the top layer has the ability to put one in touch with those that they have lost. Many a desperate man has walked to their doom in the smoke. Indeed, the legend warns that lingering too long with the lost is a sure way to join them beyond the pale.

Geography

The caldera sits on a small mountain on the side of the Little Sister. Technically, the caldera sits at the peak of its own small mountain, but many do not think of it this way, since the mountain lacks a peak, and since the caldera's edge is so close to the slopes of the Little Sister. The surrounding earth is covered in resilient little shrubs and trees. The mountain is volcanic, and one would expect there to be much in the way of foliage. There are many thriving trees and thick forest at the bottom of the small unnamed mountain which houses the Pit, but closer to the caldera itself, the plant life seems to die out. The reason for this can perhaps be attributed to the extremely cliffy rocky terrain, and the diligent efforts of the mountain goats that roam the Molehill Mountains. Regardless of the reason, many people take this as evidence that the caldera is a cursed, dangerous place that is worth avoiding. 
The stone near the top of the mountain is soft and layered, and the legends about the caldera describe the crumbling stone as a manifestation of the hunger of the smokes. The terrain is said to have crumbled and thrown individuals back into the poisonous smoke to die of their fall and the smog. Of course, more level headed skeptics say that the climbers simple could not climb as carefully after breathing in the toxic gases, and rarely fail to point out the silliness of describing a mountain as hungry.

Localized Phenomena

Whether hallucinations or magical visions, the people that leave the caldera have confirmed that they have heard or even seen their lost loved ones in the smokes. Some come away with closure, whereas others curse the caldera for only giving them a few short minutes with their loved ones, hacking up toxic smoke and eyes streaming with tears.
This could easily dismissed as hallucination, were it not for the ones that leave the mountain with knowledge it seems they could not otherwise have. One particularly compelling story is of a dwarven noble who searched for years for the buried treasure of his late uncle, and was only able to find it after visiting the Pit and breathing the caldera's smoke.

Alternative Name(s)

Prelore's Caldera

Type

Crater / Crater Lake / Caldera