This grand journey begins in the south of Hauts-de-France, on the foothills of the Soissonnais. Ciry-Salsogne stretches out in the hollow of the Vesle valley, surrounded by agricultural plateaux and limestone slopes. Marked by the clashes of both World Wars, the area retains a rich reconstruction heritage in Soissonnais limestone, at the foot of the famous underground quarries of the Aisne.

To do:

• Église de la Nativité-de-la-Sainte-Vierge in Ciry-Salsogne: Rebuilt in the interwar period by architect Édouard Monestès, discover this remarkable Art Deco style church built from limestone. Its geometric stained-glass windows and streamlined volume bear witness to the Picard architectural revival.

• Cave dwellings and ridge trail (2h00): Set off on a walking hike on the heights of the village towards the ancient creutes, these underground quarries that served as shelters for soldiers in 1914-1918.

• Aisne Valley cycle route: Hop on your bicycle for a bike ride linking neighbouring villages along the peaceful meanders of the Aisne.

The Fort of Condé-sur-Aisne

A few kilometres from Ciry-Salsogne, this semi-buried military giant of the Séré de Rivières system impresses with its kilometres of ashlar vaulted galleries, hidden beneath dense forest cover.

Heading north along the Oise, the landscape opens out onto the plains of the old navigation canal linking La Fère to Saint-Quentin. Vendeuil occupies an age-old strategic position, embodied by its ring of bastions erected in the 19th century to secure the river passage. Between dark bricks and masonry casemates, this stage builds a bridge between military structures and rich artistic collections of the Aisne basin.

To do:

• Fort of Vendeuil: Take a guided tour of the exterior and corridors of this stronghold encircled by water-filled moats, designed to guard the outlets of railway and river routes. The structure preserves its masonry firing posts and monumental entrance gate.

• Jeanne d'Aboville Museum in La Fère: Step through the doors of this art museum located just minutes from Vendeuil for a guided tour of a prestigious collection of Flemish, Dutch and French paintings from the 15th to the 19th century.

• Municipal ponds and loop of the Oise in Vendeuil (1h30): Head to the riverbanks for a shaded walk around the landscaped water bodies, renowned for coarse fishing and watching wild ducks.

The Marais d'Isle National Nature Reserve Quickly accessible north of Vendeuil, this unique urban marsh is home to a maze of reedbeds where you can glide in an electric boat amidst hundreds of waterbirds.

This stage crosses the beating heart of the Battle of the Somme. Between the labyrinthine meanders of Cappy, the waterside town of Bray-sur-Somme and the fortified plateau of Bapaume, the journey alternates between river nature and solemn tribute. White chalk slopes overlook a mosaic of ponds bordered by rustling poplar groves.

To do:

• P'tit train de la Haute-Somme and port of Cappy: Board an authentic narrow-gauge steam train winding along the chalk cliffs and marshes of the Somme. Extend with a stroll on foot around the river port of Cappy.

• Pond basin and narrow streets of Bray-sur-Somme: Stroll through the old market town at the foot of the 12th-century Saint-Nicolas church, then enjoy a river kayaking session on the calm waters of the coastal river.

• The underground passages and the keep of Bapaume: Take part in a guided tour of the underground galleries of the medieval bastion of Bapaume, a strategic crossroads of Artois coveted since the time of Charles V.

The Vaux Viewpoint and the Somme Loop This viewpoint perched on the chalk cliff offers a spectacular panorama over the turquoise ponds of Haute-Somme winding at the foot of the hills.

Crossing the borders of Ostrevent, water continues to dictate the landscape along the Sensée valley. Arleux is surrounded by peat bog ponds created by historic peat extraction. Renowned for its secular agricultural know-how, the town is inseparable from the traditional smoking of garlic plaits and market-gardening marshes.

To do:

• The ponds of the Sensée in Arleux (2h00): Stroll along the dykes and wooden footbridges for a peaceful walking hike between reedbeds and traditional fishermen's huts.

• Smoking workshop of Ail Fumé d'Arleux: Step inside a craft workshop for a plaiting demonstration and discover the secrets of smoking with sawdust and peat, which gives this exceptional condiment its distinctive aroma.

• Canal du Nord cycling loop (2h00): Head to the towpaths for a bike ride linking ancient mills and the marshes of Écourt-Saint-Quentin.

Arleux smoked garlic soup This comforting local broth, simmered with PGI Arleux Smoked Garlic, potatoes and butter, served piping hot with golden croutons.

The landscape transforms radically as you approach the former coal-mining basin. Maisnil-lès-Ruitz nestles at the foot of the first Artois hills, whilst Richebourg extends across the plain of the Pays de l'Alloeu. Here, the silhouettes of slag heaps stand alongside vast state-owned forests and memorial cemeteries bordered by weeping willows.

To do:

• Parc d'Olhain in Maisnil-lès-Ruitz: Explore this vast 450-hectare forest estate during a Nordic walking session or a mountain bike ride, whilst admiring the medieval fortified castle of Olhain surrounded by water-filled moats.

• Le Touret Indian Memorial and military cemeteries of Richebourg: Take a moving historical tour of this white-stone commemorative cloister erected in memory of the soldiers of the Indian Army who fell on the Artois front.

• Ridge trail of the Artois hills (2h00): Climb scenic paths for a walk on foot offering panoramic views over the twin slag heaps of 11/19 in Loos-en-Gohelle.

The Château d'Olhain A true lowland medieval fortress set on its clear-water moats, this 13th-century castle preserves its keep, outer bailey and original drawbridge in perfect condition.

Approaching French Flanders, Saint-Omer stands out as a pearl of art and history, guardian of France's last market-gardening marsh still in cultivation. Between red-brick townhouses, magnificent abbey ruins and dense networks of watergangs, the town cultivates a unique way of life centred around water.

To do:

• Sailing in the Saint-Omer marsh: Board a traditional wooden escute or bacôve for a guided boat ride through this maze of canals lined with floating market-gardening plots.

• Cathédrale Notre-Dame and ruins of Saint-Bertin: Admire the soaring vaults of the cathedral housing a 16th-century astronomical clock, before taking a walking stroll in the romantic park surrounding the remains of Saint-Bertin Abbey.

• La Maison du Marais: Visit this modern museum space to understand the wildlife, flora and hydraulic works created by the monks to drain the plain.

The Romelaëre Ponds Nature Reserve This protected area laid out with wooden pontoons is explored on foot right at water level, between giant reedbeds, water lilies and colonies of great cormorants.

The itinerary ends facing the sea, at the narrowest point separating France from England. A world-renowned lacemaking city, Calais combines maritime modernity, Flemish facades and endless beaches of blond sand swept by sea spray. Ferries parting the waves and the offshore wind bring a sense of absolute freedom to conclude the journey.

To do:

• The Calais Dragon and the seafront promenade: Take your seat on the back of this monumental reptile of steel and wood for an unusual animated ride along the redeveloped beach, punctuated by views of the English cliffs on a clear day.

• Museum of Lace and Fashion: Step through the doors of this authentic 19th-century factory for a guided tour with live demonstrations on immense Leavers looms.

• Place d'Armes and City Hall belfry: Climb the 75 metres of the UNESCO-listed belfry for a circular panorama over the strait port, before admiring the statue of the famous Burghers of Calais sculpted by Rodin.

Cap Blanc-Nez and its chalk cliffs A few minutes west of Calais, these dizzying 134-metre-high cliffs plunge sheer into the waters of the English Channel and offer a striking spectacle under the shifting lights of the strait.