I don't know what it is but Medellín felt very sterile and generic. It could have been any big city anywhere. Marc and I didn't spend too much time here as we didn't think there was too much to see and it was more of a stopover on the way to Cartagena.
We did visit the Botanic Gardens which were lovely and Botero's fat statues beckoned.
Other than that we didn't really do much else but I think we were saving ourselves for Cartagena!