Where to live south of DC

Most of the posts on reddit asking for Maryland cities around DC name cities on the north side. I'll be working about 45 minutes south of DC but would like to live close to DC. preferably close to a metro line that goes into DC. Any suggestions? Walkable or bikeable would be nice.

Also, if anybody knows, are you allowed to park overnight at the Metro parking lots? I would like to be able to walk to the Metro or at least park there for the weekend and go into DC.

Most of the posts on reddit asking for Maryland cities around DC name cities on the north side. I'll be working about 45 minutes south of DC but would like to live close to DC. preferably close to a metro line that goes into DC. Any suggestions? Walkable or bikeable would be nice.

Also, if anybody knows, are you allowed to park overnight at the Metro parking lots? I would like to be able to walk to the Metro or at least park there for the weekend and go into DC.