This paper focuses on the predominating east-west orientation of Iron Age graves (5 th century BC to the 13 th century AD) and the reasons that could have caused the custom. Based on the data of Baltic mythology and their reflections in folklore, the authors argue that the mythological conception of grave orientation is closely related to the mythological path of the Sun and the image of souls leaving the world of the living. Given the astronomical opposition of the Sun and the Moon, the hypothesis is justified by the fact that, when the graves of men and of women in the Baltic burial grounds adhering to the east-west axis, were oriented in opposite directions, the burial customs could have been affected by the mythological images of the heavenly family: the Sun (wife) and the Moon (husband).