Fourtrees

Fourtrees (known by the Twolegs as Druid's Hollow) is a group of four tall oak trees located in a hollow, that the Clan cats have held their Gatherings at since the early days of the Clans.

Description
In the middle, there is a steep-sided clearing and in the center is a large rock called the Great Rock,[4] which is noted to have jagged edges.The Clan leaders use it to look down on the Clans and share their news during Gatherings.They are also referred to as the Great Oaks.

Mythology
The battle that created the Clans  took place at Fourtrees. They are told that they must gather once a moon at Four-trees, to share the news of how their Clans were doing.