The eclectically styled, English-inspired palace crowning the Península de la Magdalena was built between 1908 and 1912 as a gift from Santander to Spain's royal family, who used it every summer until 1930. Detailed 45-minute guided tours (in Spanish) show you oak floors, bronze chandeliers, surprisingly simple bedrooms, a carved chestnut-wood staircase and what was the king’s study.

　　Visits are limited to weekends only in summer, when the palace hosts the Universidad Internacional Menéndez Pelayo (www.uimp.es), a global get-together for specialists in all sorts of disciplines.