As the seat of the diocese for the Episcopal church, the National Cathedral doesn't disappoint. I've only ever seen anything to equal it in Europe. The glass is fantastic and it's so magnificent. The gardens are also terrific. Nice little gift shop, if you like churches at all, don't miss this. Getting there is tough, you have to take the Metro and a bus, or drive and hope to find a space in a neighborhood around the grounds. They are supposedly trying to make it better.