I used all the words beginning with Y from my dictionary. I even used Dutch words beginning with IJ or ij. Now I am at the end of my imagination! Perhaps this?
Decoration on the outside of Rådhuset, City Hall, in Oslo.
Yggdrasil: the tree of the Universe in Scandinavian mythologyYggdrasil(// or //; from Old Norse Yggdrasill, pronounced [ˈyɡːˌdrasilː]) is the tree of the Universe and center of the divine world in Scandinavian mythology. The roots of that big ash grow in the three underworlds: the world of the death, the world of the frost giants and the world of men. The branches spread over the world.The tree unites earth and heaven and the underworld.
If Ragnarok draws near, Yggdrasil will tremble and a man Lif and women Lifthrasir will survive the holocaust and flood. From these two people the earth will be repeopled and mankind will start a new cycle of time. Yggdrasil is the source of all new life.
In Norse mythology, Ragnarök is a series of future events, including a great battle foretold to ultimately result in the death of a number of major figures (including the gods Odin, Thor, Týr, Freyr, Heimdallr, and Loki), the occurrence of various natural disasters, and the subsequent submersion of the world in water.