I love how The Renwick Gallery constantly changes up their exhibition. They keep you on your toes making you want to go back and visit. Their current exhibition is this "Parallax Gap", which you can read more about here. See below for a few photos! 

The one thing I love about DC is their museums. I love being immersed in them and could probably hop from one museum to another all day. They also happen to make great (free) photo op locations, in case you're looking for some fun insta worthy spots, and did I mention they're free?