Goshinboku

The was where Kikyō bound Inuyasha 50 years ago in the Feudal Era with her arrow at the brink of her demise. It also plays an important role with the other Tree of Ages when Inuyasha must defeat the son of the Hyōga clan.

The Tree of Ages somehow brings a special connection between memories of the past and present. And serves somewhat a telepathy connection between the Feudal Era and the present when Kagome and Inuyasha converse with each other. The Tree of Ages is also the maker of the Bone-Eater's Well (seeing that if one Tree of Ages fails in survival, the Bone Eater's Well is sealed and thus the present would be plunged in an everlasting winter).