The (in)famous Borgia family came from my area. This was their palace in the city. It started to be built in 1484 by Rodrigo de Borja, who was the city's bishop. Later on, he moved to Rome and became Pope Alexander VI. Nobody knows for sure if his children ever stayed in this palace (probably not, they were far too busy creating their black legend in Rome), but he had statues of them (and of himself) made and sent there; you can see photos in the windows. The façade doesn't look too impressive, but the inside of the palace is - there is even a garden in a patio.
This palace, while being in the city centre, is some strees away from what in the middle ages was the "noble quarter". The Borgias belonged to the nobility of the countryside, and they were not considered important enough to have their palace with the city's noble people. So the statues were sent to remind everyone of the power they had achieved.
Nowadays, it houses the regional parliament and is open to be visited on some days every year.
Ian