If I recall rightly I went there some years ago.It was kind of small but had a lot of historical ranges.
At the time there was a small group of guys that played there who also attended the HMGS cons(Historicon,FallIn,Cold Wars)
Not far away in Chantilly there is a huge store named Game Parlor.They have a lot of product with some oop stuff.I got Clan War and Starship troopers stuff there in the last 3 years.
What kind of things are you interested in ? If you have any interest in ACW there are tons of battlefields close by too.
you should have come over in July,Historicon is in Fredericksburg which is about 45 minutes down I95.
edit I think they moved to a bigger place since I was there last.If Doug Ray is still the owner he is a really nice guy.