Today, the Somme is the artery through one of the prettiest regions of northern France. The river begins its 245km journey across Picardy as a spring of exceptionally clear water that bubbles out of the chalk landscape near the village of Fonsommes. It is a wooded, peaceful spot, befitting a river whose name derives from a Celtic word meaning "tranquillity".
But way downstream, the Somme bisected the battlefront of what became the bloodiest day's fighting in the history of the British Army.
On 1 July 1916, the British Expeditionary Force attacked on a 19km front north of the river, with most of the French forces to the south. The meeting point of the two armies (at the marshy hamlet of Curlu) was a determining factor in the choice of battleground, despite the advantageous position enjoyed by German troops who occupiedhigher ground and had been able to dig their trenches deep into the protective limestone.
On the day the attack began, the British alone suffered 60,000 casualties and by 18 November that year, when the battle ended, the dead and wounded on both sides numbered more than one million. The British and French forces had penetrated fewer than 10km into German-occupied territory from their starting position east of Albert, failing to take the nearby towns of either Bapaume or Peronne. The gentle countryside of the Somme is filled with reminders of that ferocious struggle. More than 130 British military cemeteries can be found in the area and among the memorials the best known is the Memorial to the Missing at Thiepval. This art deco arch, designed by Sir Edwin Lutyens, stands 45m high and is visible for miles around. It commemorates the 73,000 British and South African troops who have no known grave. A nearby visitors' centre (open 10am-6pm, admission free) houses a permanent trilingual exhibition of texts, photographs and videos about the Battle of the Somme and the Great War.
Peronne and Albert, the towns at the heart of the battle zone, also have museums devoted to the conflict. The latter recreates what soldiers experienced with atmospheric exhibits in an underground gallery at le Musée Somme 1916, in Rue Anicet Godin (open 9am-6pm daily, €4; www.somme-trench-museum.co.uk). To see trenches as they were during the battle, visit Newfoundland Memorial Park near Beaumont-Hamel.
An equally powerful reminder of the conflict is the 100m-wide Lochnagar Crater, near La Bourselle. It was created minutes before the start of the ill-fated advance on 1 July 1916 by the detonation of a 27-tonne mine placed beneath the German front lines in tunnels dug by British engineers.
The Circuit of Remembrance is a 60km signed route that links the main battle sites and memorials. Start at the tourist offices in either Albert or Peronne, where you can also hire bikes to follow the circuit. You can find more details and download a free audio guide to the routefrom somme-battlefields.com.
Nearly a century after the fighting began, the Somme has many dimensions beyond the fundamental sense of tragedy. Long stretches of the sluggish, meandering river have been turned into a working canal which links with the rest of F"ce's canal network and makes it possible to explore by barge or cruiser.
A good starting point is the attractive village of Cappy on the prettiest section of the upper Somme, where colourful waterlilies abound and peat-digging has left a patchwork landscape of lakes. Charming villages such as Bray-sur-Somme, with its striking church in the Flamboyant Gothic style and Suzanne, with its 17th-century chateau, are well worth a visit. The undulating countryside between Méricourt and Péronne also provides some fine walks along the towpath with views from the high points, particularly from the Belvédère de Vaux, across the patchwork of lakes and fields.
Another way to enjoy the surroundings is from a slow steam train on the narrow-gauge railway running from Froissy to Dompierre. Originally built to carry munitions to the front, it now takes tourists on a 15km round-trip, though you will have to wait until May to enjoy it.
Since the region of Picardy can also claim to be the birthplace of Gothic architecture, you should not miss the cathedral at Amiens. Miraculously spared by Second World War bombs, the 13th-century church in Place Notre-Dame is both the world's largest Gothic building and a Unesco World Heritage Site.
Its must-see features include the astonishingly harmonious façade and the view over the city from the cathedral towers, for which you must cope with 307 steps.
On the edge of Amiens, the unique hortillonages are "floating" market gardens, whose plots are separated by little canals. The city's best-known resident was Jules Verne, who lived in an elegant, 19th-century house where he wrote 20,000 Leagues Under The Sea, Around The World In 80 Days and many other novels and short stories. Visit his former home, now a museum, at 2 Rue Charles Dubois (closed Tuesdays, Saturday and Sunday mornings in winter; €7; 00 33 322 45 45 75; amiens.com/julesverne).
Amiens is also the best place to enjoy Picardy's cuisine. Not to be missed in springtime is lamb from the salt meadows of the Somme estuary (gigot de pré-salé) accompanied by locally grown vegetables.
You can also enjoy fish dishes enhanced by the flavour of salicorne or samphire. Game and eels, particularly smoked, make an appearance on menus further inland. And duck appears in a variety of guises, the best known of which is pâté de canard d'Amiens prepared en croute, possibly with pistachio and foie gras.
The city is also famed for macaroons (les macarons d'Amiens), a confection based on honey and almonds, while the town of Abbeville downriver has its own speciality cake, le gâteau battu, in the shape of a chef's hat, with the consistency and flavour of a rich brioche.
Abbeville is also the place to see the Collegiate Church of St Vulfran. According to poet Victor Hugo, the last rays of sun caressing its towers were a sight to cherish.
His comments were later echoed in The Ode of Remembrance, taken from Laurence Binyon's 1914 poem For The Fallen: "At the going down of the sun and in the morning, we will remember them."
Travel essentials: Picardy
* If travelling from the UK by car, the gateway to the Somme is Calais – either by ferry from Dover with P&O (0871 664 6464; poferries.com) or SeaFrance (08705 711 711; seafrance.com), or via the Channel Tunnel with Eurotunnel (08705 35 35 35; eurotunnel.com).
* Hotel de la Basilique, 5 Rue Gambetta, Albert (00 33 3 22 75 04 71; hoteldelabasilique.fr). Doubles from €76.
* Specialist UK companies that organise tours to the Somme include Battlefield Tours, whose two-night visit costs from £340 (0121 430 5348; battlefieldtours.co.uk) and Holts Tours, whose holidays include a four-day walking tour from £685 (01293 865 000; holts.co.uk).
* You could also engage an English-speaking guide via the tourist offices at Albert (9 Rue Gambetta; 00 33 3 2275 1642) or Peronne (16 Place Andre Audinot; 00 33 3 2284 4238).
* Somme Tourist Office: 00 33 3 22 71 22 71; somme-tourisme.comReuse content