In Norse mythology, the realm of the dead is called Hel, ruled by the goddess of the same name. Hel receives those who die of illness or old age, contrasting with Valhalla, where warriors slain in battle go. This duality reflects the Norse understanding of death and the afterlife, highlighting the importance of bravery in life. Hel is often depicted as a gloomy place, but it plays a significant role in the cycle of life, death, and rebirth in Norse belief.