Second only to the Pan-Himalayan Railway in Tibet which opened in 2005, the Lirna-Huancayo line soars 4829m (15839 ft) up into the Andes, a masterpiece of engineering and a thrilling ride. It took 38 years to build the 335 km (209 mi) railway, including some 59 bridges, 66 tunnels, and 22 zigzags where the train switchbacks up sheer cliff faces. Its completion in 1908 opened the huge mineral and agricultural wealth of the Andes to market at Lima and the port of Callao. It was, and still is a working train; and that's why it works so well as a visitors introduction to Peru.
It's a comfortable train, and it needs to be. For six hours you climb steadily from sea level at Lima to the frozen wilderness of the high Andes, feeding your growing altitude headache with coca tea from the trolley. When you stretch your legs at-what is still thought to be the world's highest station, Ticlio (4758m/15606 ft), you may gasp for -air and need the help of the Oxygen Matron who patrols the train. Most people do. The cold is bitter but the scenery is breathtaking. It gets, even better as you revive, watching flowing robes and llamas raising dust in the settlements of the altiplano.
At La Oroya, you change tracks and direction. Nothing grows around La Oroya. It is the smelting centre for a collection of mining towns nearby, all overhung with the smell of sulphur. After the fantastic mountain panoramas,before this section, it's a relief to leave the peaks and treeless tundra behind at Jauja, and descend through the fertile greenery of the Mantaro Valley, one of the greatest of all Andean craft centres. By the time you reach Huancayo, you feel you've travelled through the heart of Peru's economic future as well as its highland geography.
WHEN TO GO
Year-round (according to the often theoretical schedule), but between October and March, at least the Huancayo end of the trip will be balmier.
TIME IT TAKES
11-12 hours (in daylight: depart Lima 7.00 am, via Ticlio, La Oroya, Concepcion, arrive Huancayo 6.00-7.00 pm).
The Desamparados railway station in Lima, built with flourish in 1912.
Coming out of a tunnel, along a cliff-edge gallery through an arch onto the Infiernillo Bridge over a deep chasm - a standout among spectacular thrills en route.
The oxygen Matron, whose presence on the train is required by law; for which you will be grateful.
YOU SHOULD KNOW
At the railway's highest point, there is 40 per cent less oxygen in the air than at Lima. People describe feeling drunk, shell-shocked or nauseous, and may stagger about or slump gasping.
But help is at hand, and it will pass as you descend.