Half Life 2: Dominion

Citadel Primary Entrance Gateway - A massive fortified portal at the Citadel's base, featuring two towering blast doors reinforced with alien alloys. The approach is guarded by multiple Elite Overwatch snipers in elevated positions and automated pulse turrets tracking all movement. A shimmering blue force field spans the entire entrance, requiring authorized ID implants for deactivation. Scanners constantly patrol overhead, while a checkpoint station processes the few permitted visitors through invasive biometric verification. The security perimeter extends 100 meters outward with motion sensors embedded in the pavement. Even authorized Civil Protection officers must surrender weapons before the inner barrier grants access to the Citadel's processing terminal.

The gateway is imposing, with its colossal blast doors glinting in the light, surrounded by a high-tech security perimeter. The blue force field shimmers ominously, and the presence of snipers and turrets adds to the tension of the area.