A six-day itinerary aboard the new Costa Verde Express.

Courtesy of Trenes TurAsticos de Lujo

State-owned railways arent usually associated with upscale travel.

Visitors exploring the town of Santillana del Mar.

A passenger train crossing a bridge in Spain

The Costa Verde Express near the medieval town of Viveiro, Spain.Credit:Courtesy of Trenes Turísticos de Lujo

Its so romantic, isnt it?

said a flight attendant from Chicago who sat near me during lunch.

The water was ice-cold, but the sunset was unforgettable.

Exterior of building in a town in Spain, with flowers on the balconies

Visitors exploring the town of Santillana del Mar.

Besides, the train was stationery every night, so there was no rush.

When I returned to my cabin, there was a square of dark chocolate on my pillow.

I went to sleep to the rustling sounds of birds nesting in the stations tiled roof.

Pair of photos from Spain, one showing cave paintings in a museum and one showing modern architecture of a museum

From left: Replicas of cave paintings at the Altamira Museum; the Guggenheim Museum Bilbao.From left: Toni Anzenberger/Redux; Getty Images

Its like a living museum, said our guide, Daniel Escudero.

The shops on the main street sold Cantabrian anchovies, wild-boar sausages, andorujo,a local brandy.

I met two pilgrims from Canada who were buying butter cake, the towns signature treat.

Pair of photos from Spain, one showing a man hiking with mountains in the background, and one showing a historic town square

From left: Hiking in Picos de Europa National Park, in the Asturias region; the main square and cathedral in Santiago de Compostela.From left: Chris DoAl/iStockphoto/Getty Images; Peter Hirth/laif/Redux

They had walked 186 miles of the Camino de Santiago and had 300 more to go.

TheseUNESCO-protectedmountains are home to rare wildlife, including Iberian wolves and shrewlike desmans.

We returned to the train for lunch and continued to Oviedo, the regions stately capital.

We were touring the historic center when it started to pour.

The final dinner black-truffle ravioli and seared sea bass was served aboard the train.

Champagne flowed as we raised a glass to the crew.

It was 3 a.m. when I finally got to bed.

Despite the incessant rain, the atmosphere was electric.

Galician bagpipers played by the entrance to the plaza.