My top picks for excursions from Bilbao
Bilbao has a lot to see around the city and if possible you should keep a couple of days for day trips. All of my favorite locations are well connected from Bilbao by public transport (bus), though driving is certainly the easiest way to get there.
Lekeitio is a colorful fishing port with a history of whaling located an hour away from Bilbao. Today it is a nice village with many bars and restaurants, and summer concerts. There are also nice beaches and the island of San Nicolas accessible during low tide.
Mundaka is popular with the surfing community and is known for its left wave. It also plays a leading role in Basque mythology, being the place which gave the region its first Lord. The Urdaibai biosphere is also nearby. Mundaka is less than an hour from Bilbao.
Castillo de Butrón
This is a well-kept secret, Butron Castle is just 30 minutes from Bilbao. It was originally a medieval castle remodeled about 150 years ago to its present look. You should certainly visit if you like castles in remote places but you can only see it from the outside because access is permanently closed. Driving is the best way to reach Butron Castle and you can plan this visit en route to Plentzia.
You must sample the world famous wines of La Rioja
and Laguardia is the prettiest town in this region. For Laguardia, the best way to get there is to drive or change a bus at Haro.
If you like watersports, walking along a nice promenade with bars, on a beautiful beach...then Plentzia is perfect for a visit just 30 minutes by car or an hour on the metro from Bilbao.
Zarautz is a classy, laid-back, but an upscale coastal town with the longest beach in the Basque region. It is also famous as Queen Isabella’s summer getaway. You can see a lot of aristocratic mansions along the beach.