A main historian-tourist objective is seeing what corroborates events in the life of Vlad III Tepes. Poinari Citadel is the mountaintop (a manageable walk with mild switchbacks up from the road) castle where, it is said, the Turks were threatening, and Vlad's wife so feared being taken that she hurled herself off the parapet to her death.
Poienari Citadel. Vlad escaped from Poinari Citadel, and went to another castle at Targoviste. See http://www.davidstuff.com/historical/vlad.htm; and the more tourist-oriented version for the story at http://www.romaniatourism.com/dracula-legend.html/
This fortress was built in the 1300's and became the main defense point for the Basarab rulers. See http://www.exploringromania.com/poienari.html