The weirwood is a species of deciduous tree found all over Westeros. The five-pointed leaves and the sap of weirwoods are blood-red, while the bark and wood are white. Most weirwoods have faces carved into their trunks. This was done by the Children of the Forest in ancient days, and is now done by the freefolk and other descendants of the First Men. In some cases, sap can collect, giving the trees red eyes. They have even been know to drip sap, as if the trees were crying.
Weirwood and the Old Gods
Weirwoods are considered sacred to the followers of the Old Faith. The Children are said to have carved the faces in the weirwoods during the dawn Age before the coming of the First Men across the narrow sea. It is said that through the faces the old gods watch over the followers, and bear witness to important events. Also the Greenseers of the children of the forest could also see through the eyes of the weirwoods, to see far off places. Since the trees have no sense of time, the Greenseer can see into the past or present when looking through the eyes of a tree.
Weirwoods grow wild in the groves of the forest, after the First Men took up the Old Faith, they created godswoods, groves within their castles and villages where a single Weirwood known as a heart-tree, was planted so the gods could be worshiped.
The Weirwoods are used to bear witness to important events such as marriages and it said that it is impossible to lie in the presence of a weirwood.
Weirwood and the Andals
With the invasion of the Andals came the Faith of the Seven. The weirwoods came to represent the Old Faith and they were mostly cut down. With the exception of a few remaining heart-trees, the only place south of The Neck where weirwood groves remain is the Isle of Faces, where the Children and the First Men agreed to peace. The Andals were never able to conquer the North, however, and the Old Faith remains strong there. Weirwoods still grow in the forests of the North, and are very prevalent beyond the Wall.
Things made of weirwood
The wood of the weirwood is an excellent building material because it does not rot. Their wood can be used for making bows, spears, and arrows; Ygritte and Brynden Rivers had weirwood bows.. It can be used to make furniture. (The meeting table of the Kingsguard is white weirwood in the shape of a shield, and the throne of House Arryn in The Eyrie is also carved of Weirwood.) The wood is also used in architecture, such as the Black Gate of Nightfort and the rafters of Harrenhal. The House of Black and White's main door is made of weirwood and ebony as are chairs in it.
Black Gate at Nightsfort
Coldhands leads Samwell Tarly and Gilly to the Black Gate to find bring someone back that Coldhands was sent to find. Once through the gate, Sam and Gilly climb up a well with stairs cut into the side to the kitchen. In the kitchen Bran, and his group were sleeping. Sam’s arrival scares them, and Sam is caught up in Meera’s net before the fire can be stoked so that the situation can be assessed. After Sam tells them that he is to lead someone through the gate for Coldhands Bran decides to go, so Sam leaves Gilly behind, and guides them to the gate. Since only a sworn man of the Watch can open the gate, Sam had to be there to open the gate. When they get to the gate it can be seen that it is white Wierwood with an old, wrinkled, shrunken, pale face with an extremely faint glow. The face opens its eyes and asks “Who are you?” Sam replies:
I am the sword in the darkness, I am the watcher on the walls, I am the fire that burns against the cold, the light that brings the dawn, the horn that wakes the sleepers, I am the shield that guards the realms of men.
The face responds “Then pass” and the door opens wide. All that remains is a great gaping mouth in a ring of wrinkles. As they pass, Hodor does not dip low enough, and a drip of water falls on Bran that is as salty as a tear.
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