About an hour-long car drive from a down called Hervás, you'll find Cuacos del Yuste, the famous town known for the palace where Carlos V went off to "die well."
It's one of the most interesting palaces that I've seen in Spain. Not only for the beautiful gardens, the church, and the ranches, but for the palace that holds a multitude of Emperor Carlos V's personal belongings. Seeing these items makes him seem more human and takes us to another time. His chair-bed he used for transportation after he was struken with the gout and couldn't walk, the bed where he spent his last few years, the family portraits, his bedside books, the coziness of his bedroom, or his reading chair, all provide real-life examples of how he spent his last years.
Also, the admission ticket is a good price. The palace also houses interesting exhibitions and collections.
All in all, it's a must-see site if you are in Cáceres. Highly recommended!