Santillana del Mar is much more than the Caves of Altamira. Already in the ninth century the town was in the Monastery of Santa Juliana, giving way to the prestigious Collegiate Church of Santa Juliana in the twelfth century, the first and most important exponents of Romanesque architecture in Cantabria. Around the collegiate and its beautiful cloister, from the late twelfth-early thirteenth century, developed a core of people who lived times of great economic splendor, as evidenced by the richness of the many mansions and palaces that make up this town.

In its cobbled medieval streets can also be found many artisan shops and delicious taste milk biscuits, snack popular in town.