Charles Street, known for most of its route as Maryland Route 139, runs through Baltimore and the Towson area of Baltimore County. On the north end, it terminates at an intersection with Bellona Avenue near Interstate 695 (I-695). At the south end, it terminates in Federal Hill in Baltimore. Charles Street is one of the major routes through Baltimore, and is a major public transportation corridor. For the one-way portions of Charles Street, the street is functionally complemented by the parallel St. Paul Street, including St. Paul Place and Preston Gardens, Maryland Avenue, Cathedral Street, and Liberty Street.

Towson is an unincorporated community and a census-designated place in Baltimore County, Maryland, United States. The population was 55,197 as of the 2010 census. It is the county seat of Baltimore County and the second-most populous unincorporated county seat in the United States.