The Palace Ruins was a location in Jak 3. The collective part of Haven City that was nearly destroyed beyond recognition when the Palace collapsed. The Ruined area is technically part of the majority of former Main Town, as well as a recently-converted section of the northern Gardens and part outside the walls of Haven itself. It connects to the Catacombs and Ruined Stadium.
Jak only entered the Ruins once in an attempt to access the Catacombs below the Palace, but the Dark Makers' army was already present and proved too much to handle for him alone. He was rescued however, by Damas who brought a Slam Dozer, which they promptly used to travel through the Ruins.
As the name implies, Palace Ruins is nothing more but a massive ruined area of Haven City. Although formerly Main Town, it is not even recognizable anymore save for the futuristic design of the buildings and the water that is still present, remnant of the old canals. There were numerous barriers erected throughout the ruins, powered by separate pillars which had to be destroyed to advance further.