Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is San Sebastian (45% of total searches to Bay of Biscay). The next most popular destinations are Bilbao (37%) and Biarritz (11%). Searches for hotels in Santander (7%) are also popular.
KAYAK users have found double rooms in Bay of Biscay for as cheap as $19 (Bilbao) in the last 3 days. The average price is $195.