Cindergrove

The  is a forest in a caldera of a volcanic mountain that has a portal to the Elemental Plane of Fire. Guarding this portal, called the "Rift of Flame", is the druidic village Pyrah located on the outskirts of the forest.

Forest
All the trees in the forest are long dead hardened, blackened and petrified. There is not a leaf among them, and most of the wood is either gray or black from being charred, burned, or dying over time and being petrified.

On the floor of the forest are piles of burnt-away brush, ash, and whatever else once was considered life amongst the boughs of these trees when they grew there.

The center of the forest, is the source of molten rock sprays. There is a large crevasse bisecting the center of the forest, about 40 feet across and about five feet wide that is a pool of slowly roiling lava. The air around it is heavily warped by this intense heat that's being released, and all the trees that are immediately around it are all warped and bent and have been burnt to near lack of recognition.

Portal to the fire plane
To enter the fire plane from the Cindergrove, permission must be asked from the mountain to open the portal to the fire plane.

Once the mountain has granted permission the lava will begin to grow more and more active, sending off little spittles of rock. It will beginning to slowly spin with a strange sucking sound, almost like sludge is being pulled through a tube. With a final shift of the ground, and cracks from the trees, bits of broken branch and tree begin to fall and hit the ground. The lava will pull down into a vortex that disappears into the crevasse and creates a spinning whirlpool of molten rock in the crevasse and seems to disappear 20 feet below. The portal can now be entered by attempting a leap of faith.

To complete her third trial of her Aramenté, Keyleth has to go into the Elemental Plane of Fire to find a stone spire. After asking permission of the mountain the portal opens before her. Without hesitation Keyleth jumps in, after casting Protection from Energy on herself. Vox Machina all jump after her into the portal.

After Thordak escaped from the fire plane though the portal the Cindergrove was left in ruins. The Cindergrove is but a fraction of what it once was, most of the trees thrown hundreds of feet from the center and scattered amongst the top of the once-volcanic mountain. The mountain has been blown apart in areas, sections of large black stone have been pushed up into jagged obelisks, pits of molten rock that have been punched through the floor and have gathered into the pools of lava.