San Antonio, Texas map

San Antonio sits on the Balcones Escarpment: north of Loop 1604 the land rises into limestone hills, south of downtown it flattens into the South Texas brush country. It is the southwestern corner of the Texas Triangle, 80 miles from Austin, 200 miles from Houston and 150 miles from the border at Laredo.

Military bases ring the city: Joint Base San Antonio combines Fort Sam Houston, Lackland and Randolph. The metro includes New Braunfels, Schertz, Seguin and Boerne.

Bexar County holds 1,256 square miles and counted 2,009,324 people in 2020; San Antonio is the seat and covers roughly two-fifths of the county's land. Its neighbours are Kendall to the north, Comal to the northeast, Guadalupe to the east, Wilson to the southeast, Atascosa to the south, Medina to the west and Bandera to the northwest. Converse, Universal City, Live Oak, Leon Valley, Helotes, Kirby, Windcrest, Alamo Heights and Terrell Hills are separate incorporated cities inside the county, and the last three are enclaves surrounded by San Antonio.

The San Antonio River rises from springs a couple of miles north of downtown, loops through it in a tight horseshoe bend and turns south toward the Gulf. The River Walk, or Paseo del Río, follows that bend one level below the streets, reached by stone stairs from the bridges at Commerce, Market and Houston. It exists because of a flood: the water that came down the bend in September 1921 killed dozens of people downtown. The engineering answer was Olmos Dam upstream and a bypass channel cut across the neck of the horseshoe, and the architectural answer was Robert Hugman's 1929 plan for a landscaped commercial walkway along the old bend, built by WPA crews in the late 1930s.

The walkway is no longer only that loop. The Museum Reach runs north past the San Antonio Museum of Art to the Pearl, and the Mission Reach continues about eight miles south along a restored, re-meandered channel past Concepción, San José and San Juan to Mission Espada, with a hike-and-bike path the whole way.

Five missions were founded along this stretch of river between 1718 and 1731. The northernmost, San Antonio de Valero, is the Alamo, on Alamo Plaza in the middle of downtown. The four to the south — Concepción, San José, San Juan Capistrano and Espada — make up San Antonio Missions National Historical Park, strung along Mission Road and the Mission Reach trail. San José, the largest, still has its full walled quadrangle, church and granary; Espada retains the aqueduct that carried its acequia over Piedras Creek. In 2015 UNESCO inscribed all five together as a World Heritage site, the only one in Texas.

San Antonio has been a garrison town since the Spanish presidio of 1718, and the military still owns large blocks of the map. Since 2010 the three installations have been run as a single command.

The hills north of Loop 1604 are more than scenery. Rain falling on the faulted Edwards limestone there sinks straight down into the Edwards Aquifer, which supplies most of San Antonio's drinking water and surfaces again as Comal Springs at New Braunfels and San Marcos Springs at San Marcos. Because whatever sits on a parking lot over the recharge zone can end up in that water, building there is regulated more tightly than anywhere else in the metro, and the city has spent sales-tax money for years buying land and conservation easements across the zone. It is a large part of why the built-up area thins out where it does on the northern edge of the map.

The city's districts are strung along the river and the two loops rather than around one center. The South Texas Medical Center, in the northwest quadrant near Loop 410 and Wurzbach Road, works as a second downtown: UT Health San Antonio, University Hospital and dozens of other institutions sit inside it, with USAA's campus and UTSA's main campus a few miles further out along I-10.