Six days in Wallonia: Three citadels on one river, and hardly a visitor on it

The seat of the prince-bishops who ruled Liège as an independent state until 1794, rebuilt from 1526 around two courtyards. The first is open to walk into: sixty squat columns, each carved differently, with grotesque faces meant to be read as a warning about folly. It is a courthouse now, so the yards are the visit.

Underneath the square, everything that stood here before: a Roman villa, a Merovingian church and the foundations of the three cathedrals of Saint Lambert, the last demolished by revolutionaries. A modest doorway on the square leads down into a great deal more space than you expect.

A brick staircase of 373 steps straight up the hillside to the citadel, built in 1881 so that the garrison could reach barracks without passing through the bars of the old town. Gardens and houses either side, the whole valley behind you at the top.

A pub kitchen making boulets the same way for decades in a room nobody has redecorated, which is the point. Cash, brisk service, and the best plate of food on this route for under twenty euros.

An eight storey mansion of red brick and pale stone, built around 1600 by a man who made a fortune selling gunpowder to the Spanish crown. It now runs the city's archaeology, glass, weapons and decorative arts through one route, and the medieval metalwork of the Meuse valley is the part to slow down for.

A squat Romanesque church in banded stone holding the brass font cast by Renier de Huy around 1118: five baptism scenes in high relief on a bowl carried by twelve oxen. One of the great works of medieval Europe, in a parish church with a coin box for the lights.

The brasseries between the old town and the quay do a set lunch for less than a sandwich costs in Flanders. Take whichever has a handwritten board outside.

Gothic, 13th to 15th century, promoted to cathedral in 1802 once the old one had been demolished, which is why its treasury holds what it does: the reliquary Charles the Bold gave the city in 1471 as an apology for having sacked it three years earlier, a kneeling gold duke presented by Saint George.

The old church tower that became the town's belfry, one of the 56 in Belgium and northern France recognised together as a single UNESCO site. Belfries were the symbol of a town's right to govern itself, which in this part of Europe was a right worth ringing a bell about.

A small museum of medieval and Renaissance religious art from the region, and the reason to come is the goldsmithing: the treasure of Oignies, made by a lay brother named Hugo in the 13th century, is some of the finest metalwork to survive from the Middle Ages anywhere in Europe. Recorded commentary in English.

A chocolate maker with an old-fashioned cafe attached, doing hot chocolate in a range of strengths that make the powdered version at home look like a mistake. The right pause on a first afternoon.

The terraces along the Sambre and around the Place du Marché aux Légumes are where Namur eats. Prices here are a third below Flanders and the kitchens keep going later than you would guess for a town this size.

One of the largest fortresses in Europe, on the spit where the Sambre meets the Meuse, with foundations from the 10th century and layers added by Spanish, French, Dutch and Prussian engineers over the next eight hundred years. Guided visits go down into the tunnels, which are cold, low and much longer than the part you walk. The cable car from the river does the climb in five minutes.

There is a restaurant on the citadel with the whole valley below it, and a dozen cheaper options five minutes down the hill. Either works; the view costs about ten euros extra.

The archaeology of Roman and medieval Namur in a small municipal museum, worth an hour on a wet afternoon and skippable on a fine one. The building and the streets around it are half the pleasure, in a town that looks more French than Belgian.

A fortress on the cliff a hundred metres above the Meuse, held at various times by the prince-bishops of Liège, the French and the Dutch, and rebuilt after each of them. The visit covers barracks, a 19th century prison, tunnels and a display on the fighting of 1914. The view down the river is the reason everybody comes.

The church on the riverbank under the rock, with a bulbous pear-shaped tower that is the town's signature. The Romanesque church that stood here was crushed by a rockfall in 1227 and the Gothic replacement took centuries; the pieces of it do not quite match, which is part of the charm.

A museum in the town about the beer that began at the abbey a kilometre up the road in the 12th century, the monks who made it and how it turned into one of the biggest brands in Belgium. It is not brewed here any more, which the museum is honest about, and the tasting at the end is generous.

The restaurants along the river empty out when the last coach leaves, and the cliff above them turns orange for about twenty minutes at sunset. Sit outside if you can.

A cave found in 1904 on the far bank, with small waterfalls, white stalactites and a walk of about fifty minutes on made-up paths. It is a straightforward visit rather than a scramble, it is 13 degrees inside whatever the weather is doing, and it is the best of several caves in this stretch of the valley.

Dinant station stands five minutes from the bridge on the near bank. Buy something for the train in the town: the platform has nothing.