Stella's Mom S.
Yelp
Absolutely fascinating place and nearly unknown, even to locals. It's in Silver Springs, MD, so not on the standard tourist track, and few other tourist "destinations" nearby. This version of the museum opened in the fall of 2011.
It is a museum related to health and medicine, and while few, if any, of the exhibits are truly gross, they can be extremely graphic. Fascinating, but graphic. The NMHM grew from an Army Museum, so a heavy portion of the collections are military-related - various Civil Was weapons, projectiles, examples of damage caused, early prostheses, examples of death by various diseases, early hospital trains & ships, Civil War surgical equipment ... a replica of an intact MASH unit .... exhibits highlighting the Gulf War and its specific human impacts ...
They have their fixed exhibits and a selection of rotating ones as well - several hundred years' of early microscopes, early x-ray equipment , the flip-through man (a person who was sectioned from head to toe in very thin segments, which were then sealed & mounted horizontally so you can flip from one end to the other, the first dialysis machine ever used, and much more. (They do have their own website if you want to look up the details.) When my boss had to be in DC for a conference, I told her to be sure to take a side trip here - they were having an exhibit of hairballs and she was in heaven! (Well, yeah, some of us find different things fascinating.)
It's under military jurisdiction so they do ask for ID when you go there, and they note license plate and registration numbers of vehicles, but that's about the extent of their screening. Ample parking - free, and museum entry is also free. Very handicapped accessible. Hours are a bit shorter than some standard museums, so might want to double-check before you go. Can be a bit noisy sometimes because they have a fair amount of school field trips that come here.