Brightwater Keep is a castle in the Reach. It is the seat of House Florent, a vassal house holding fealty to House Tyrell of Highgarden. The castle is located west of Highgarden near the west coast of Westeros, also close to the headwaters of the Honeywine River.
In the books
In the A Song of Ice and Fire novels, House Florent of Brightwater Keep also lays claim to Highgarden, due to a closer blood relationship to House Gardener, the Kings of the Reach before Aegon the Conqueror extinguished their line on the Field of Fire. As a result of this, the Florents are surly and reluctant bannermen to the Tyrells.
Following the Battle of the Blackwater, House Florent is attainted by the Iron Throne and stripped of lands and titles. Brightwater Keep is granted to Ser Garlan Tyrell, the second son of Lord Mace Tyrell, who has been cut from the series so far.
Old Oak · Red Lake · Goldengrove · Bitterbridge · Tumbleton · Grassy Vale · Cider Hall · Ashford · Horn Hill · Brightwater Keep · Bandallon · Honeyholt · Oldtown (Citadel · Hightower · Starry Sept) · Uplands · Blackcrown · Three Towers · Sunflower Hall · Arbor