The Big Shell is the fictional multibillion-dollar pollution refinery facility, located in outer New York City harbor featured as the main locale in the video game Metal Gear Solid 2: Sons of Liberty. It was constructed after an alleged oil spill, caused by the destruction of an oil tanker two years prior to the game's events, polluted the entire area.

However, the truth about Big Shell is that it is actually a cover up for a new Metal Gear project by the name of Metal Gear Arsenal. Arsenal Gear comes equipped with tactical nuclear launch bays as well as a fleet of mass produced Metal Gear RAYs. It is also designed as a floating fortress to protect the computer program "GW" which controls, filters and censors digital information in an attempt by the Patriots to stop the free flow of information to insure their secrecy and control over world politics.