Oldest eight theme parks owned by Six Flags

Including those owned by the company's predecessors Cedar Fair and the original Six Flags. Cedar Point in Sandusky, Ohio (opened 1870). Six Flags New England in Agawam, Massachusetts (opened 1870). Dorney Park in Allentown, Pennsylvania (opened 1884). Knott's Berry Farm in Buena Park, California (opened 1920). Six Flags Great Escape in Queensbury, New York (opened 1954). Michigan's Adventures in Muskegon, Michigan (opened 1956). Frontier City in Oklahoma City, Oklahoma (opened 1958). Six Flags Over Texas in Arlington, Texas (opened 1961).