Clark Freeport Zone is a redevelopment of the former Clark Air Base, a former United States Air Force base in the Philippines. It is located on the northwest side of Angeles City and on the west side of Mabalacat City in the province of Pampanga. It is located northwest of Metro Manila. The zone is a former US military base and has modern infrastructure facilities, generous fiscal and non-fiscal incentives, professional support services and other amenities. Today, Clark forms the hub for business, industry, aviation, education, and tourism in the Philippines as well as a leisure, fitness, entertainment and gaming center of Central Luzon.
The plan for the 4,400-hectare (10,868-acre) main zone and 27,600-hectare (68,172-acre) sub zone is to transform the zone into an airport-driven urban center targeting high-end IT enabled industries, aviation and logistics related enterprises, tourism and other sectors.
In 1995, following years of neglect since the 1991 base closure due to the eruption of Mount Pinatubo, cleanup and removal of volcanic ash deposits at the former Clark AB began. The former base re-emerged as Clark International Airport and Clark Special Economic Zone (CSEZ). The airfield infrastructure was improved to make it one of the most modern in Asia, and a second parallel runway was built. The former base is now home to a golf resort, a number of industrial buildings, casinos, landmarks, and retail establishments. It also hosts the annual Balikatan exercises between the United States and Philippines Armed Forces.
Though many events still occur at Clark, critics have said that the American government left some residual toxic chemicals that now affect the groundwater near the base. Native Filipinos who live nearby show signs of the adverse effects of these chemicals, such as mercury, resulting in leukemia, gangrene, and other severe diseases and health problems. The United States denies responsibility for these actions. A CRC (Clearwater Revival Company) report claimed that "until a more detailed investigation of uncontrolled hazardous waste sites at Clark AB is completed no conclusions can be reached about the present or future safety of the groundwater supply basin." Several organizations, such as FACES (Filipino American Coalition for Environmental Safeguards) and PTFBC (People Task Force for Bases Clean-up), have attempted to begin the detoxification process on the bases.