Fort Monroe's Casemate Museum 1

Not sure if they've closed up Fort Monroe lately or not, but when we were there you could just drive right on. The Fort Monroe's Casemate Museum is awesome for history buffs. Union and confederate memorabilia inside the Casemate which makes it a fascinating place to walk through. Evidently, Jefferson Davis was held there for a while. Certainly neat for any TRADOCers stationed up at Eustis (Army’s Training and Doctrine Command was HQ'd there).
Free last time we went, but that might have been because of military ID. Docents were there to do guided tours if you wanted, but you're welcome to walk through on your own, too.
Entryway into the inner fort is small, so if you drive a bigger vehicle like a truck, I'm not sure where you'd park.