In the United States and other countries , the county seat is the capital of a county . ( Ellicott City , the county seat of Howard County , is the largest unincorporated county seat in the United States , followed by Towson , the county seat of Baltimore County , Maryland . ) The county courthouse and county administration are usually located in the county seat , but some functions may also be conducted in other parts of the county , especially if it is geographically large .