The estuary of the Loire is a remarkable natural space at the intersection of two bird migration paths, and is home to nearly 200 protected animal species. Upstream, the historical wealth of the Loire Valley and its castles is breathtaking (Château de Chenonceau and Château de Chambord, to name only two). Further along, between Nantes and Saint-Nazaire, right until the ocean 60 km (37 mi.) away, the river becomes more pristine, lined with remarkable landscapes that slowly transforms into an open-air museum mixing nature, art and industry.