These domains appear on the kingdom map randomly. Only Suzerains can find them with the help of explorers.
In the garrison of each such domain there’s an army of monsters with a monster hero. When a new Stonehenge appears on the map, one of the 9 possible runes is generated at random in his hero’s bag. In case of a successful attack mission on a Stonehenge the initiator of the mission takes the rune provided that he has previously studied Alchemy to lvl 2 and his hero has a at least one spare slot in his bag. The life span of a Stonehenge is 72 hours or until it is destroyed.
When an attack mission is sent to a Stonehenge, hero monsters from the nearest Stonehenges can bring their armies as assistance. Bear in mind that the garrison in the Stonehenge where the assistance mission came from stays unchanged. The number of outgoing assistance missions in a Stonehenge is unlimited , the number of those incoming is limited by 2 .