Rockville Martial Arts & Learning Center
The manager/owner of the school does not know martial arts. I don't mean that he studied martial arts and is no good. I mean, he never studied martial arts. Period.
There was one good instructor, (http://www.siramainternational.org) but he left after he got his green card. All his black belt students left with him.
There was an attempt to inject quality into the school by a nearby good school (http://www.worldclassicmartialarts.com). The grandmaster (who is an excellent instructor and runs a great school himself) unfortunately sent a young student of his to be the master of the school. The kid was great technically, but poo - absolute poo - as a teacher.
A great place for babysitting your kids after school. Nice mats. No pillars in the middle of the dojo.
Full contact sparring (with pads). Great place to learn how to get beaten up.