Where is located the Llanos region?

Answer 1

It is in Colombia and Venezuela.
Los Llanos are the plains of Colombia. The city of Villavicencio is essentially the gateway to the llanos. An area known for large cattle farms as well as petroleum.
http://en.wikipedia.org/wiki/Llanos

Ciudades de Los Llanos Político-administrativamente, los Llanos forman parte del territorio de dos países: Colombia (en donde se les da el nombre de Llanos Orientales) y Venezuela. La división politico-administrativa es:

Answer 2

in Venezuela. Llanos region is marked with yellow on the map.