Going for a drive on a Sunday afternoon in the Romansch-speaking high country in Graubunden, Switzerland, where road and railroad crisscross each other frequently in the Alps, often on century-old stone bridges. I was staying with a friend-of-a-friend in nearby Chur, who happens to be an architect and railroad-buff. As we were driving, he noticed a train coming along, and he proceeded to speed up, saying "I know of a good place to watch the train come out of a tunnel!" So, faster and faster we curved downhill, zigzagging with the train.
A few minutes later, we came out of the mountains and pulled off the road into a cornfield—just in time to watch the Glacier Express zip across the Landwasserviadukt—its six limestone arches, up to 20-stories tall, were built in 1901.