These ancient buildings range from the Romanesque style of the Middle Ages ​ — with its typically thick walls and heavy, curved arches — ​ to the ornate and dramatic baroque of later centuries.
Nende hulgas on nii paksude müüride ja ümarkaartega romaani stiilis ehitisi kui ka hilisemast ajast pärit rikkalike kaunististega barokkstiilis kirikuid ja kloostreid.