Six Flags AstroWorld, also known simply as AstroWorld, was a seasonally operated amusement park in Houston, Texas. Owned and operated by Six Flags, the park was situated between Kirby Drive and Fannin Street, directly south of I-610. The park opened on June 1, 1968, and was developed originally and constructed as part of the Astrodomain, the brainchild of local philanthropist and former Houston mayor Roy Hofheinz, who intended it to complement the Astrodome. The Hofheinz family sold AstroWorld to Six Flags in 1978. Notable rides featured at the park included the Texas Cyclone, a wooden roller coaster built in 1976 that was modeled after the well-known Coney Island Cyclone, and Thunder River, considered the world's first successful river rapids ride when it opened in 1980. WaterWorld, an adjacent water park, was acquired and added to AstroWorld in 2002. Following declining revenue, rising property value, and other issues facing Six Flags, the company closed AstroWorld permanently after its final day of operations on October 30, 2005, the final night of Fright Fest. Many rides were sold at auction or relocated to other Six Flags' properties, and demolition of the remaining structures was completed by mid-2006. History Planning and construction Judge Roy Hofheinz, who was one of the original owners of the Houston Astros baseball team and spearheaded the lobbying effort that resulted in Harris County financing the construction of the Astrodome, founded the "Astrodomain" holding company after the Astrodome's opening in 1965. It owned in south Houston surrounding the Astrodome. Hofheinz continued to develop the Astrodomain, creating AstroWorld (1968), the Astrohall convention center (which hosted twice-daily stagings of the now-defunct Ringling Bros. and Barnum & Bailey Circus in 1969; Hofheinz had acquired the circus in December 1967), and four hotels with a capacity of 5,600 guests to serve visitors: the Astroworld Motor Hotel (with a private suite for Hofheinz on the ninth floor), Holiday Inn-Astroworld, Howard Johnson Motor Lodge-Astroworld, and Sheraton Inn-Astroworld. In 1967, Hofheinz initially denied that preliminary work for an amusement park had been underway, but later announced on September 16 that approximately half of the remaining land, , was being developed for a park to be named "Astroworld". Hofheinz showed an architectural model of the park and announced that Randall Duell and Associates had designed it; Duell, a Hollywood set designer and architect, had previously designed Six Flags Over Texas. An initial $25 million investment paid for extensive