Houston is a sprawling metropolis in Texas, extending to Galveston Bay. It’s closely linked with the Space Center Houston, the coastal visitor center at NASA’s astronaut training and flight control complex. The city’s relatively compact Downtown includes the Theater District, home to the renowned Houston Grand Opera, and the Historic District, which pairs 19th-century architecture with trendy restaurants. Houston was founded in 1836 on land near the banks of Buffalo Bayou (now known as Allen's Landing) and incorporated as a city on June 5, 1837. The Houston Theater District, located downtown, is home to nine major performing arts organizations and six performance halls. Of the 10 most populous U.S. cities, Houston has the most total area of parks and green space, 56,405 acres (118 km2). Houston has a population of 1.1 million.