How long to stay in Cartagena vs Medellin?

Hey, gonna be visiting Cartagena and Medellin for about 10 days total so wondering what those that have been to both would advise in terms of how long to stay in each and any must do’s/recs.

I’m going with a buddy and besides the obvious partying, we’re looking to explore the City during the day and cram in activities (nature stuff, hiking, water adventures… etc.) We haven’t talked about renting a car or motorcycles but open to it if there’s anywhere to go outside the cities on day trips. I hear Guatapè is worth visiting as well?

Thanks in advance for any tips!