I originally read that Guatapé, a two hour trip outside of Medellin, was busy and crowded on weekends, and so, not being a fan of crowds, planned to visit on a Monday as a daytrip.  But some things in our Medellin schedule had to get rearranged, and so we had to change our daytrip to fall on a Sunday.  It turns out this was the best decision that could have happened – the vibe of Guatapé on a Sunday was one of my most fun days in Colombia.