Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Bilbao (98% of total searches to Biscay). The next most popular destinations are Santurtzi (1%) and Portugalete (0%). Searches for hotels in Mundaka (0%) are also popular.
KAYAK users have found double rooms in Biscay for as cheap as €20 (Bilbao) in the last 3 days. The average price is €190.