Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Santander (88% of total searches to Cantabria). The next most popular destinations are Castro-Urdiales (4%) and Santillana del Mar (4%). Searches for hotels in Noja (4%) are also popular.
KAYAK users have found double rooms in Cantabria for as cheap as $25 (Santander) in the last 3 days. The average price is $125.