Houston is a large human settlement called a city.
A city is a large and permanent human settlement . Houston . With a census-estimated 2014 population of 2.239 million within an area of 667 sqmi , it is also the largest city in the southern United States and the seat of Harris County . Located in Southeast Texas near the Gulf of Mexico , it is the principal city of the Greater Houston metro area , which is the fifth-most populated MSA in the United States . Houston is the most diverse city in Texas and has been described as the most racially and ethnically diverse major metropolis in the U.S. .