The Palace of the Warrior-King was a fortress located on one of the many hills overlooking the city of New Athens on planet Macedon III. The palace was constructed of black stone and was topped by crimson-capped towers. The palace became a famous attraction to Federation tourists who visited the planet.
The palace could be seen from the terrace of the Hotel Terra, and was observed by Lieutenant Commander Nyota Uhura when she stayed at the hotel during her shore leave in 2277. (TOS - Star Trek II Short Stories short story: "Under Twin Moons")