My favorite place in Santander, i think the Royal Palace is based on Balmoral castle and is now used as part of the university of Cantabria. The best part is the grounds and view, the Palace is on the top of a hill with the Bay of Biscay on one side and Santander bay on the other. There is a penguin and seal enclosure which is free to visit (feeding time is 5 o'clock) and replicas of old Spanish sailing ships.