Lost City is a Gears of War: Judgment multiplayer map included in the Lost Relics Map Pack. It features a walkway turntable in the center of the map containing the Boomshot, which can be rotated via four separate switches.
The ruins of this ancient city were once a major archeological find. Despite sitting empty for centuries, the hydro-powered aqueduct and canal systems were still in working order and proved that the ancient Serans had a remarkable grasp of engineering and architecture. Like so many projects, excavation was abruptly halted when the Locust emerged and changed the face of the planet. Now, every Seran city sits as empty and lost as this one.