Kaer Morhen, the Keep of the Old Sea, is an ancient, secluded stone fortress tucked deep within the rugged Blue Mountains of Kaedwen. Serving as the historic headquarters and training grounds for the Witcher School of the Wolf, the fortress is mostly a ruined shell of its former glory following a fanatical assault decades ago. It features a vast valley containing trial grounds, hidden caves, and mountain elements. Only a handful of witchers return here to survive the harsh winter months, making it a place of deep nostalgia, fading brotherhood, and ancient secrets.