Amazing - Must Visit
Just about all the Museums are FREE!!! and they are actually awesome! very easy to spend entire day in each one if you are doing them properly! Definitely a very Underrated City!
Insider Tip:Go to the Newseum! pretty much the only one you have to pay for but its really AMAZING!! and give yourself the whole day to get it done, even then you might need 2 - but thats ok because when you buy a ticket its valid for 2 days!