Quantico, made famous by several TV shows, is a real town in Prince William, Virginia. Quantico is about 36 miles outside of Washington, DC. Marine Corps Base Quantico is the largest Marine Corps base in the United States. Other agencies, such as the FBI Academy and the Naval Criminal Investigative Service, are also located on the base, though sadly, NCIS isn't actually filmed there.
Quantico has something for everyone. For gym addicts, there are four of the best gyms in the town, and one of them is a highly recommended Crossfit gym. In addition, there are movie theatres, museums, golf parks, and many more rivers and lakes. If you want a great all-rounder-town, then Quantico is the one you should visit.
The Amtrak Northeast Regional and Amtrak Carolinian stop in Quantico from Baltimore, Philadelphia, Washington D.C., and New York. If you're driving, know that you'll have to pass through the Marine Corps Base and present valid driver's license to pass on to town.