Dallas, Texas, the state's second largest city and the seat of Dallas County. It is situated on rolling prairie along the Trinity River in the northeastern part of the state, some 30 miles (48 km) east of Fort Worth. Texans often refer to Dallas as “Big D.”

The Trinity River, running roughly northwest-southeast through the city, nearly bisects Dallas. The downtown business district, centrally located just east of the river, has a prominent skyline of towering hotels, banks, and office buildings.

Elevations in Dallas range from about 450 to 650 feet (137 to 198 m) above sea level. Maximum dimensions are approximately 26 miles (42 km) north-south and 21 miles (34 km) east-west.

Dallas is the dominant city in a large metropolitan area that includes, in addition to suburbs, Fort Worth and much productive farmland. Suburbs include Irving, Arlington, Garland, Grand Prairie, Mesquite, and Richardson. University Park, Highland Park, and Cockrell Hill are independent cities surrounded by Dallas.