It becomes impossible to ignore the Four Comers once Route 160 enters Colorado’s Montezuma County: chevroned signposts spring regularly out of the sand and scrub, urging you towards it. Even if you had never heard of it before, did not know that it is the only point in the USA where four states meet, you are soon curious: it begins to seem like a major station, a Golgotha or Gethsemane, on this well-worn tourist pilgrimage.

The size and sleekness of the trailers and travelling homes heading towards it are eloquent of its significance. These are not the trailers you have grown accustomed to seeing in small towns in the South and Midwest – those shiny aluminium goldfish bowls which sit parked in backyards until the ball game in the next town, when they get hitched on to pick-up trucks and towed out to the ball park to serve as adjuncts for tailgate parties. Not these; these are no ordinary trailers, they are Recreational Vehicles (RVs) – if not quite palaces, then certainly midtown condos, on wheels.

You only get a real idea of how big they are when you try to pass one on a two-lane road in a Honda Civic which lost its fifth gear 8,000 miles ago. Before you are past the master bedroom, are barely abreast of the breakfast nook, that blind curve that seemed so far away when you decided to make a break for it is suddenly right upon you.