Georgetown is a city and also the county seat of Williamson County, Texas, United States with a population of 28,339 at the 2000 census. Southwestern University, founded in 1840, is the oldest university in Texas and is located in Georgetown, about 1/2 mile east of the historic square. Inner Space Cavern is a cave found on the southside of the city, just off Interstate 35. Sun City Texas is a large retirement-oriented and age restricted development. Sun City Texas, constitutes a significant part of the population of Georgetown.Georgetown has a notable range of Victorian commercial architecture. In 1976 a local historic ordinance was passed to recognize and protect the significance of the historic central business district and in 1977 the Williamson County Courthouse Historic District, containing some 46 contributing structures, was listed on the National Register of Historic Places.Georgetown is called the "Red Poppy" Capital of Texas for the many red poppy (Papaver rhoeas) wildflowers planted throughout the city which bloom each Spring. Georgetown also holds a Red Poppy Festival in April each year. The festival brings in around 30,000 visitors annually.Geographically, Georgetown lies across the Balcones Escarpment,