Forget the pre conceived notions about Medellín. Pablo Escobar, most dangerous city in the world, etc. Those stigmas still live on, but this is certainly not the reality of the city today.
Medellín has been my favorite place to visit and explore in Colombia so far. It reminds me quite a bit of Vancouver, both in the climate and the city itself. There is so much to do and explore, it is truely a gem. There are plenty of foreigners visiting the city, it seems the word is out. Come visit while you can.