|  In northern 
        Peru, there are a wide variety of environments formed by the Andean Cordillera 
        and the rivers that dissect them. In western Cajamarca, the deep valley 
        cut by the north flowing Río Marañón produces an Inter-Andean formation 
        between the high-elevation "jalca" of the central Cordillera and the eastern 
        escarpment [6°30'-9°00'S latitude]. Environments change rapidly as you 
        decend from nearly 4500 m to 800 m and then ascend again to equal heights, 
        and all over a very short lateral distance. At the bottom of the valley 
        exists a unique desert formation that includes columnar cacti and thorny 
        shrubs, many of which are only found in the Río Marañón valley.   
       |