Fairfax Station, Va.
Length: ~4.6 miles
Description: It’s a loop around a gorgeous lake.
Cons: It’s not quite 4.5 miles, not quite 5 miles. It’s a trip from D.C. The trail gets a little tight southeast of the marina for about a half mile.
Pros: It’s beautiful, the loops are long, and emerging from the woods onto the dam is a nice change of pace.
Tricky Points: A marathon isn’t exactly 25 miles, or 26 miles for that matter, round numbers aren’t everything. If you are a little particular about your mileage totals, try running a few loops without finishing on a whole number and realize that the world didn’t end.
Afterward: A sandwich at Pizza Boli’s afterward in Huntsman Square and some ice cream at Baskin Robins.