Saturday:

Reception at the Parador de San Marcos in León, followed by lunch and a short guided tour of the city (magnificent stained glass in the cathedral, storks nesting above the Romanesque façade of San Isidro . . .), then by train up the Torio valley to the foot of the mountains at Matallana. Eastwards across the great shoulders of bleak upland which run south from the mountains, through Boñar to the former coal mining town of Cistierna for the evening meal and overnight.

Sunday:

Breakfast while the train continues from Cistierna over the sinuous route to Guardo, another former centre of coal mining. Then by coach to visit the remarkably well-preserved remains of the Roman villa at Olmeda, and the Romanesque architecture of Carrión de los Condes, Villalcázar de Sirga (lunch) and Frómista, the latter town also boasting a grand flight of locks on the long-disused Canal de Castilla.

A land of wide skies, storks, and in spring the most amazing variety of roadside flowers. Back to the train at Mataporquera, through heather-clad uplands to the southern bank of the vast Ebro reservoir and down into a landscape of cliff-fringed plateaux and deep valleys. Sotoscueva, just below the Ojo Guareña show cave, is the idyllic, pastoral overnight base (there is a village bar just down the road from the station!)

Monday:

Breakfast diners watch the floor of the Cadagua valley drop away on the left of the train, to leave the railway clinging to the mountainside at the foot of a limestone precipice. This is El Cabrio - the fearsome (in the days of steam) descent from the Cordillera watershed at El Cabrio. Beyond Balmaseda, with its gatehouse-crowned bridge over the river, through increasingly industrialised landscapes to Bilbao (lunch and Guggenheim Museum visit).

The afternoon is spent traversing the line to Santander, described in an early 20th century Baedeker guide as one of the most scenic rail journeys in Europe. Birds of prey soberly regard the train's progress from telegraph poles; in springtime the cuttings and embankments are carpeted with primroses; in October you might glimpse countless ephemeral purple crocuses. The Cantabrian pasture aromas - a blend of freshly-mown grass, manure and milk - are intoxicating, stimulating an appetite for dinner, the latter taken in genteel and elegant Santander, the overnight stop.

Tuesday:

Westwards through pastoral Cantabria to Torrelavega, whose dense, sinister apartment architecture might best be described as 'vertical', the air thick with fumes from the nearby SNIACE cellulose works. By coach to world-famous medieval Santillana del Mar (lunch) and the replica cave paintings at Altamira.

Onwards by train through the timeless Saja and Escudo valleys, where herons fish from rocks in the rivers, to reach the clifftops (for the very first time on the journey!) between Unquera and Llanes. After a pause to explore this lively Asturian fishing port, along the foot of the limestone bulk of the Sierra de Cuera to Ribadesella, the finishing point of the annual Descenso del Sella canoe race, for dinner and overnight.

Wednesday:

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