While savouring the first meal to stimulate our taste-buds in four days, I wondered idly about the location of the train station we needed to return to Cuzco.

But as we paid the bill, a final twist in the trail presented itself. A low grumbling thunder – incongruous to our setting, but vaguely familiar – grew to a crescendo before slowly giving way to a high-pitched hissing and squealing that seemed to emanate from some strange and unexpected mechanical behemoth. The light from the front of the restaurant – which for some reason had no outer wall – was suddenly snuffed out. Blocking the view of the narrow high street, a full-sized train had drawn up alongside the building. Without batting an eyelid, our waitress suggested we better get on if we wanted to get back to Cuzco that night. We stepped from the restaurant into the carriage.

Such a wonderfully surreal surprise is a good argument for not reading your guidebooks too carefully. My better-read friends looked unperturbed. Their loss.