Arlington is considered to be the second-largest "principal city" of the Washington metropolitan area. Arlington County is located in northeast Virginia and is surrounded by Fairfax County and the Falls Church to the southwest, the City of Alexandria to the southeast, and Washington, D.C. to the northeast directly across the Potomac River, which forms the county's northern border. Other landforms also form county borders, particularly Minor's Hill and Upton's Hill on the west. A number of the county's residential neighborhoods and larger garden-style apartment complexes are listed in the National Register of Historic Places and/or designated under the County government's zoning ordinance as local historic preservation districts. Many of Arlington County's neighborhoods participate in the Arlington County government's Neighborhood Conservation Program (NCP).
Each of these neighborhoods has a Neighborhood Conservation Plan that describes the neighborhood's characteristics, history and recommendations for capital improvement projects that the County government funds through the NCP. Arlington ranks fourth in the nation, immediately after Washington, D.C. itself, for park access and quality in the 2018 ParkScore ranking of the top 100 park systems across the United States, according to the ranking methodologies of the nonpartisan Trust for Public Land. Arlington has consistently had the lowest unemployment rate of any jurisdiction in Virginia. In October 2008, BusinessWeek ranked Arlington as the safest city in which to weather a recession, with a 49.4% share of jobs in "strong industries". In 2010, there were 0.9 percent of the homes in foreclosure. This was the lowest rate in the DC area.