Herdstone

The campsites of Beastmen are often set up around the sacred Herdstones that are scattered throughout the dark forests of the Old World. Sometimes referred to as the Chaos Heart, herdstones are sacred to the Beastmen, and all manner of offerings are left there to appease and earn the favour of the gods; weapons, armour, the banners of vanquished foes and the corpses of mutilated enemies can all be found piled around the base of these stones. The herdstones are always erected in places of magical significance, usually over one of the baleful meteors that brought the Beastmen into being all those ages ago.[4d]

They are well hidden and there are almost always Beastmen warherds and Minotaur tribes nearby because of it. The floor of the clearing in which the herdstone stands is often strewn with an ankledeep carpet of bones, the remains of the captives taken in battle and sacrificed by the Bray-Shamans to the dark glory of the Ruinous Powers. Most herdstones are located far from human settlements, for no such settlement founded near one has survived more than a single season. They are often hidden in the darkest and most inaccessible parts of the forests, deep within caves or on mountain tops. Any intrusion within a hundred leagues of a herdstone will cause every warherd in the region to descend upon the intruder with unrelenting wrath. Sometimes, particularly powerful Minotaurs take up the role of the keepers of the herdstones, becoming the fearful guardians of these most sacred Beastmen shrines.[4d]

To gather the warbands, a raging signal fire is lit in the centre of the herdstone circle. Often, Shamans throw mind-altering herbs upon the blaze, sending up great swathes of strangely coloured smoke curling into the sky. This fire is stoked with wood and carrion, and left to burn for days on end. Over the following nights, other Beastmen will slowly gather at the sacred stones, attracted by the fire and the smell of burning fat; each arriving chieftain scratches his name or mark onto the central stone in the crude Beastman version of the Dark Tongue, known simply as the Beast Tongue, and his warband sets up camp. It is at the herdstones that most of the important celebrations and festivals of the Beastmen take place. They are the rallying points where warbands can meet and join together without fighting breaking out instantly. They are also the place for feasting, most importantly the ritualistic Champion's Feast, where the flesh of slain chieftains is consumed by the herd.

Source
pg. 14
 * Warhammer Armies: Beastmen (6th Edition)