Eighty kilometers (50 miles) long and 13 kilometers (eight miles) at the point where it enters the Atlantic, the Gironde Estuary in southwest France is so vast that as you sail along it you may think you’re at sea. The estuary, formed by the confluence of the Dordogne and Garonne rivers, was officially declared a Marine Nature Park in 2015. Sail upstream and you’ll reach Bordeaux, the UNESCO World Heritage city whose waterfront and historic center have gone through a successful urban renewal. Along the way, you pass one of France’s great wine regions, the Médoc. For centuries, Irish and British navigated these waters as wine growers and traders, and some of them also as pirates.
Also along the way, you can spot ancient cliff habitations, as well as small islands that once had fishing villages on them, but which have now reverted to nature. The Gironde Estuary is one of Europe’s most important migration and nesting sites for herons, cormorants, black-headed gulls and other birds. You can spot them on sandbanks, church towers and châteaux, as well as amid the vines that extend as far as the eye can see.