In the middle of the north Atlantic, a lighthouse juts out of the water. Inside waits a rusted bathysphere, which takes you deep under the ocean to Rapture, a city sprawling along the sea floor.

A man named Andrew Ryan, a former Soviet citizen, built the city in 1946, and the society was envisioned as the ultimate capitalistic and individualist paradise, with the elite achieving for themselves, rather than for the whole. Protected by a network of giant sea walls and consisting of a cluster of enormous skyscraper-shaped hive towers, Rapture was designed to be entirely self-supporting, with all of its electricity, food production, water purification and defense systems powered by the natural undersea currents of the ocean.

At one point Rapture's population numbered several thousand at its peak during the early 1960s, composed of those people Ryan viewed as the best examples of mankind. A large and tiered economy grew among the people, with different quality products catering to different levels of the society.

The grand Art Deco architecture is at once futuristic and archaic, but as you step into Rapture, you find the city a shell of itself. The walls are crumbling and the ocean is seeping in. The hallways are littered with corpses, those who were once the best and brightest of the world above are now mutated and mad, roaming the corridors and waiting to ambush you at every turn.