Eight thousand clay soldiers stand guard on the plain of the Wei River, far north of the Yangtze: Xi'an is the classic land extension of river cruises, and it is experienced as a journey within the journey. You leave the ship at Chongqing or Yichang, and one domestic flight or high-speed train later, the ancient Chang'an opens its gates, with one or two hotel nights replacing the cabin. The detour is easily justified: few cities in the world concentrate so much history per square metre. The change of scenery also plays its part: after the gorges and the river's brown water, here is the dry light of the North, persimmons set out to dry on low walls and the gravelly accent of Shaanxi.

The emperor's buried army

About forty kilometres east of the centre, near Lintong, farmers digging a well in 1974 uncovered one of the major archaeological finds of the last century. The pits of the Terracotta Army have protected the mausoleum of the first emperor, Qin Shi Huang, for twenty-two centuries. Beneath the immense hall of Pit 1, columns of foot soldiers emerge from the ochre earth, row after row; each face differs from its neighbour, and archaeologists continue to assemble fragments in a workshop open to view. Pits 2 and 3 display chariots, crossbowmen and the command staff. You come out strangely silent, as if leaving a cathedral.

The ramparts by bike

Back in town, the Ming city wall still encircles the old heart: nearly fourteen kilometres of intact walls, so wide you can ride a bike on them. Renting a bicycle atop a gate turns the walk into an aerial tour of the city, with moats and grey roofs on one side and modern buildings on the other. In the middle of the imperial grid, the Bell and Drum Towers have answered each other for six centuries, lit up in the evening like lanterns set above the traffic.

The Muslim Quarter

Behind the Drum Tower begins the Hui quarter, where the Muslim community carries on a trade inherited from the Silk Road, of which Chang'an was the starting point. The lanes smell of cumin and grilled flatbread; biangbiang noodles, as wide as belts, are stretched before your eyes, and yangroupao is served, a lamb soup poured over bread crumbled by hand, a comforting dish for northern evenings. The Great Mosque is hidden at the end of an alley: successive courtyards, ancient stelae and wooden pavilions make up a place of prayer with entirely Chinese architecture, founded under the Tang and one of a kind.

The Wild Goose Pagoda

South of the ramparts, the Giant Wild Goose Pagoda has raised its brick storeys since the Tang dynasty; the monk Xuanzang had the sacred texts he brought back from India translated here after seventeen years on the road. The esplanades around it come alive in the evening, when families come to walk around the fountains and the pale brick gently lights up.

Port of call at a glance

Then comes the time to head to the airport or the train station, bound for the river or for home. On the train speeding across the Wei plain, many pull out their photos of Pit 1 again, as if to confirm that these silent regiments really do exist. This stop, the farthest from the water on the whole itinerary, often remains the one people talk about most on their return.