Arlington is almost treated as an extension of Washington, D.C. as it is also home to Arlington National Cemetery, a national airport, the National 9/11 Pentagon Memorial and the Pentagon, the headquarters for the U.S. Department of Defense and the military forces. All of these landmarks make this area a bustling metropolis.
Crystal City is a very urban environment with tall buildings, plenty of traffic, and very few mature trees. Thankfully, Crystal City has plenty of well-maintained sidewalks and, like much of the greater D.C. area, is extremely pedestrian-friendly. In fact, many local businesses will often have doggie water bowls out on the sidewalks during hot summer days.
Crystal City is also a relatively flat neighborhood, meaning you and Fido shouldn't have too much difficulty getting around.The boundaries of Crystal City include 15th Street, Army Navy Drive, and 6th Street to the north, George Washington Memorial Parkway, a Metro line, and a greenway to the east, Four Mile Run and 24th Street to the south, and South Eads Street along with South Fern Street to the west. Richmond Highway is a major roadway through the neighborhood and it runs north to south, making it an area that should likely be avoided if you're not interested in maneuvering your way through traffic.
Furthermore, running along the east side of Crystal City, you will find an extension of Long Bridge Park and the Mt. Vernon Trail. To the south of the neighborhood and along Four Mile Run, you will find the Four Mile Run Trail. Both of these are great options if you are looking to extend your walk outside of the Crystal City neighborhood or if you are just looking to get away from the more urban environment.
Other nearby greenways include Eads Park, Fort Scott Park, Oakcrest Park, Nelly Curtis Park, and Virginia Highlands Park. The nearest dog park is two miles west of Crystal City and is located in Troy Park, off of South Troy Road.