The Aurora cable car provides incredible views of the west of Medellin and a view into the different aspects of its society. The cable car floats over the hills and some of the poorer areas of Medellin. It passes favelas as well as new government housing projects. When you're interested in visiting a favela, I recommend Comuna 13. Formerly Medillins most dangerous neighbourhood, but due to urban renewal rejuvenated. I walked up the barrio's hill until it didn't feel safe anymore.
Colombia has it all! High Andean mountains, beautiful Carribean beaches (think: white sands and turqoise waters), thick Amazon jungle, mysterious archeological ruins and cobbled colonial villages.