Clark, 80km northwest of Manila, is the former site of the US Air Force’s base, in use from 1903 until the eruption of Mt Pinatubo forced their hasty departure in 1991. Since then the base has been developed into the site of an international airport and the Clark Freeport Zone – a somewhat refined enclave comprising a business district, estates, casinos, golf courses, duty-free shops and upcoming restaurants. It's also used as a base by the Philippine Air Force.
Unless you have a flight from Clark Airport or a bus transfer at Mabalacat terminal in Dau there's no pressing reason to visit Clark or Angeles; the latter is synonymous with the sex industry in the Philippines. The 10,000 girls and women working the strip of tacky clubs and bars are only the vestiges of the time before the closure of the airbase, when it was estimated that 10 times as many were employed.