From publisher blurb:
Long forgotten by the people of the Rosewood Highlands, these ruins, now called Blackfalls Hall, have become the palace of the mysterious King Under the Water.
Including seven maps generously provided by Dyson Logos’ Patreon project, this supplement details over 160 locations and includes several new monsters and new ways of looking at some old favorites.
Blackfalls Hall, the Palace of the King Under the Water, is a Highlands Location located in the eastern part of the Northern Tier Hexcrawl, which is a small region of the Rosewood Highlands.
What does the King Under the Water want? What is he hiding? Who will brave the depths of Blackfalls Hall to discover its secrets and treasures?
Blackfalls Hall, the Palace of the King Under the Water, is a Highlands Location, for use with Swords & Wizards in the Highlands, a rules variant.