In the books
In the A Song of Ice and Fire novels, Uplands is the seat of House Mullendore. It is located due east of Oldtown on a tributary of the Honeywine, amongst the foothills of the Red Mountains (which give it its name). House Mullendore is a vassal of House Hightower of Oldtown rather than the Tyrells directly.
Ser Mark Mullendore of Uplands was a noted knight in the service of Renly Baratheon, noted for his trained black-and-white monkey. He switched allegiance to Stannis Baratheon after Renly's death. He lost an arm in the Battle of the Blackwater and was taken prisoner by the Lannisters. He bent the knee and swore fealty back to the Iron Throne.
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