Jeju Island, South Korea’s southernmost volcanic province, is often referred to as the 'home of 18,000 gods.' Beyond the veneer of luxury resorts and bustling tourism lies a profound mythological landscape shaped by two dominant female deities: Seolmundae Halmang, the giantess who sculpted the island’s terrain, and Yeongdeung Halmang, the seasonal goddess of wind. These legends are not mere folklore; they are sophisticated cultural narratives that explain the island's resilience and its inhabitants' deep-seated reverence for the natural world. The legend of Seolmundae Halmang transcends simple creation myths. Described as a giant so immense that she used Mt. Halla as her pillow while her feet rested in the southern sea, her story provides a physical and spiritual map of the island. One of the most poignant narratives involves her offer to build a bridge to the mainland in exchange for a set of silk undergarments. When the people failed to provide enough fabric for the final piece, the bridge remained unfinished. This story serves as a metaphor for Jeju’s geopolitical isolation and its fierce independent identity—forever longing for connection yet defined by its self-contained boundaries. In contrast, Yeongdeung Halmang is a 'visiting deity' who arrives on the first day of the second lunar month. As the sovereign of the spring winds, she traverses the coastline for fifteen days, sowing the seeds of seaweed and shellfish that sustain the local *haenyeo* (women divers). The Yeongdeung-gut rituals, recognized as a UNESCO Intangible Cultural Heritage, highlight a unique ecological contract. Rather than attempting to dominate nature, Jeju’s seafaring community offers prayers to harmonize with the unpredictable rhythms of the sea, acknowledging the goddess as the ultimate arbiter of maritime prosperity. Analytically, these 'Halmang' (Grandmother) myths signify a distinct departure from the patriarchal structures dominant in mainland Korea. They reflect a socio-cultural framework where the feminine is synonymous with creation, labor, and protection. If Seolmundae is the earth itself, Yeongdeung is the steward of its resources. These figures embody the archetypal Jeju mother—resilient, resourceful, and fiercely protective. Scholars of Jeju studies argue that this matriarchal mythological base has fostered the island's strong sense of community and its tradition of 'sunureum' (mutual cooperation). Ultimately, the legends of Seolmundae and Yeongdeung remain vital cultural assets rather than relics of the past. In an era where climate change and rapid urbanization threaten the island’s biodiversity, these ancient myths offer a timely reminder of the necessity of ecological humility. The grandmothers of Jeju continue to whisper through the wind and the stones, reminding us that progress must never come at the cost of our connection to the land that birthed us.