The central region of Texas covers the state's three largest cities: Houston, Dallas-Fort Worth and San Antonio. The limestone terrain of Texas Hill Country lies in Central Texas, as do the state's three largest rivers, the Trinity, the Brazos and the Colorado. Land for sale in Caldwell County recently totaled approximately $315 million and approximately 100,000 acres. Caldwell County ranks 81st in the Lone Star State for the combined amount of land currently advertised for sale. Of all land for sale in Caldwell County, Lockhart had the most land for sale. Caldwell County is the 239th biggest county (547 square miles) in Texas. It's located in the Blacklands South Texas region of the state.