We had a fun crossing over the border into Peru. You get into a colectivo (shared) taxi which is in an old American car like a Buwick, Cadillac or Dodge. The taxi driver handles all the border formalities and you enjoy the ride. We got to Tacna on the Peruvian side of the border after about an hour and had lunch in the bus terminal whilst waiting for our connection across the desert.
Denis managed to (mildly) upset one of the local tout/guides. He was trying to offer his services to guide us to the other bus terminal for our bus to Arequipa. Denis replied in perfect Spanish "You mean the one we get to by coming out of this building turning left, left at the next street and then straight on to the building in front".