1) I like the stories they tell In their art, architecture, stained glass, etc
2) There are a lot of cathedrals in Europe/Spain
3) Most of the treasures are contained in Cathedrals as opposed to museums. At least most older treasures.
4) The history of Spain, and other European countries lies in her churches. In them you can see the fall of Rome, the rise of the Visigoths, the Muslim invasion, the reconquista, the age of kings, the age of monasteries, the renaissance, the reformation, the counter reformation, humanism and even secularism. You can see evidence of wars, and of new worlds explored IF you know what to look for. You can see history…..and I love history.