The nature lover can't miss the Flysch rock formations that stretch for miles between Deba and Zumaia, peaceful beach-side villages of northern Spain. This enormous ancient formation was the result of millions of years of Atlantic waves slamming agains the solid cliffs along the coast. One could say that this spectacular sight answers the question of what happens when the unstoppable force meets the immovable object. Today, spiral shells, fossils, and thriving plants can be found among the curving, parallel trails. Visitors also enjoy diving, swimming and boating in the pristine blue sea along the coast. Land-lubbers will enjoy hiking and nature-watching. Whether you go on an undersea adventure or take a casual stroll along one of nature's most incredible sights, one cannot help but feel awed by this result of this eons' long battle between natural forces.