In the port area in Callao there was a small train engine on display. We were told that it was the original engine for the train that went to Machu Picchu. That was (and maybe still is) a narrow gauge line.
It may also be from the line called the Ferrocarril Central del Perú which started in Callao port, from almost the sea level, it passes by Lima city and then reach the peak-altitude of 4,818 m. in the Anticona pass (Ticlio, Lima).
There is a similar type train pictured on a so called Trencito stamp which was a stamp used to pay for mail carried by train between Callao, Lima and Chorrillos. It was issued on December 29,1865 and was a half price postage reduction. At that time the minimum postage charge was 10 cents (Un Dinero) so the new railroad rate was reduced to 5 cents.
Whatever the reason for the little engine, we always tried to take a picture of it when we went in and out of the gate.