If you will ever be in Basque Country, you have to visit Gaztelugatxe. It's an islet on the coast of Biscay, connected to the mainland by a man-made bridge. It's one of the most beautiful places that I've ever seen!
To go there you can take a bus, rent a car or, like I did, ask your new basque friends for a lift:)
I believe that it's better to go with someone who knows the way, because you can easily get lost.
The view is breathtaking!
To go on the top of the islet you have to climb the narrow path that contains 241 steps(yeah, it looks a lot, but actually it's not so hard as it seems). Once you there, you will find the church, dedicated to John the Baptist, that has a bell situated along the front of its facade. According to legend, once you're on top, you should ring the bell three times and make a wish.