Graht-oaks are giant migratory trees that house Bosmeri cities in the province of Valenwood. The graht-oaks were allowed to move by magic that was invoked at the dawn of recorded history: the founding of the Camoran Dynasty by King Eplear.
The walking tree city of Falinesti is the largest of Valenwood's graht-oaks, standing at a mile tall and half as wide. The tree that forms the city is gnarled and twisted with a gorgeous crown of gold and green, dripping with vines and shining with sap. Bosmer live in numerous natural dwellings within the mighty branches of the city, along with Orcs, Imga, and Centaurs.
Arboreal rodents, known as Kollopi, live and feed exclusively only on the most tender branches of the graht-oaks. At the time of the annual harvest in Valenwood, colonies of Imga monkeys gather these little mice by leaping around beneath the shade of the graht-oaks and picking the Kollopi from their perches.