Declared the eighth wonder of the world upon its completion, the Harris County Domed Stadium (later known as the Houston Astrodome) was the first domed stadium in the world when it was completed in 1965. Construction of the stadium began on January 3, 1962 and was not complete until April, 1965. The stadium was built to attract a Major League Baseball franchise to the city of Houston and was promoted heavily by Judge Roy Hofheinz. On October 17, 1960 The City of Houston approved plans to build the dome. Recognizing the size of the Houston market, and the significance of the stadium its civic leaders were construction, National League team owners agreed to expand and create a new team, originally known as the Houston Colt 45's into their league. The Houston Oilers NFL franchise played here from 1968 to 1996 and the Astros played here from 1965 to 1999. The Houston Texans (successor to the Oilers) play at Reliant Stadium and the Astros play at Minute Maid Park. The facility failed to meet fire codes in 2008 and parts of it have been demolished. As of 2016, the stadium is operated as NRG Stadium but without a major sports team as a tenant, its future is uncertain.
The peak of the stadium's dome stands eighteen stories above the playing field and originally consisted of skylights designed to allow natural light through the roof of the dome. As a result, the domed stadium was able to feature a grass playing field. However, the clear roof sometimes focused rays of light in ways that created an extreme glare and made it impossible for outfielders to see a baseball in the afternoon sun. In response, the skylight panels were coated in semi-clear paint. When this caused the grass to suffer from lack of sunlight, the stadium's management designed an artificial turf playing surface. As the stadium had become known as the Astrodome, the artificial surface became known as Astroturf.
The Astrodome also served as home to former the Houston Oilers following major renovations in order to accommodate the two different playing fields. In Fall of 1989, capacity for the stadium increased to 54,816 as the grandstands were extended into the outfield. The original scoreboard was replaced by new video boards in the upper deck. The two manual scoreboards were added as part of the outfield walls in both left and right fields. The Oilers later relocated to Tennessee in order to have their own stadium.
The future of the Houston Astrodome is in question, but its credentials as a historic site were confirmed by the stadium's placement on the National Register of Historic Places in 2014. The stadium has been home to national political conventions, championships of multiple sporting events, and a bout between Muhammad Ali and Cleveland Williams for the World Heavyweight Title. It also housed thousands of people who lost their homes during hurricane Katrina in 2005.