Birka

The ancient lunar city from which the Skypieans, Shandia and Birkans (Enel's ancestors) descend, who left it for the Blue Planet.

Birka is the name of the city buried beneath the Moon's crust and, at the same time, of Enel's home sky island — which he himself destroyed. A lunar mural depicts the winged peoples who, their resources depleted, descended toward the sea and skies of the Blue Planet.