Haroon I am from Medellin. There are so many places to visit in Colombia. However, you may like to ride to Los Llanos Orientales, La Sierra Nevada del Cocuy, La Laguna de Tota, San Gil, Barichara, el desierto de la Tatacoa and finally San Agustin.
I did a trip last January and rode to all these places and many more in 11 days. The places I listed before are about 400 to 500 kilometers away from each other so you wont get tired or bored!!!