Did Guatapé last Saturday. Recommendations:

1. Leave Medellín by 7am. The Peñol traffic is brutal after 9.
2. Climb the Peñol first, before town. 740 steps. Worth it. Do it before you eat lunch.
3. Take a boat on the lake. $15-20 USD for an hour. Captains will tell you stories. Bring sunscreen.
4. Eat at a lakeside restaurant in town for lunch. The zócalos around the colorful houses are best in afternoon light.
5. Leave by 4pm to avoid evening Medellín traffic.