Round Rock is a city in Texas's U.S. state, in Williamson County that is part of the metropolitan area of Austin, Texas. The population reaches 99,000. The city straddles on both sides of the Escarpment Balconies, the areas roughly east of Interstate 35 are flat and marked by the Blackland Prairie's dark, rich soils, and the western side of which mainly consists of hills. On Texas State Highway 45 Round Rock shares a shared border with Austin. Round Rock covers 36 square miles in total. Round Rock is perhaps best known as Dell Technologies' worldwide headquarters, which employs nearly 16,000 employees at their Round Rock facilities.