I took an afternoon bus to Salamanca, five hours away (SE of Santiago). This is a city I was going to cut from my itinerary if it turned out I didn't have time for it. I had the time and I'm very glad I went because it had some fantastic sites (and sights). I got there fairly late but managed to get a room (or a box depending on how you wanted to judge it) for a cheap price in the one hostel I had info for. I hurried to the cathedral to see the old cathedral, attached to the new one. It had some amazing sculpture and original wall paintings. The altarpiece was beautifully painted too. Here are some pictures. The first is St. Christopher from the S. Transept. The second is an apocalypse from the even older St. Martin's chapel off to the west of the church. The third image is the annunciation from the altarpiece.
The old city was mostly made up of yellow stone. Even the library was set in an old building (it's the one on the right with the shell motif on it). I also visited the university (founded in the middle ages and still in use! Aren't you glad our classrooms weren't like this? I've got a close up of the benches, and they don't look particularly comfortable.).
The university facade is famous. See if you can spot the sculls (I enlarged it on my camera and it is visible). I've included a close up to help.
The university also houses an old celestial ceiling. (I used to be an actual ceiling but it's now housed in a special display room.