Cartagena is a beautiful city that you should honestly add to your bucket list. When you finally go, and if you are unable to make up your mind about what to do while there, here is my list of 5 things that are highly recommended.
1. If you are crunched for time, swim with the locals over on Tierra Bomba Island. From jet skiing to eating at a slew of local spots. Here is the quickest way to find a good beach, not great, close to Cartagena. This excursion can cost you about $18. Which is inclusive of: hotel/ Airbnb pick up, a trip to and from the island, as well as lunch. Jet skiing on the island is a bit costly, it's about $70.
2. Do not visit Cartagena without exploring the historic center. There is a lot that you will be able to do. But you want to visit so you can capitalize on the backdrop of its historic streets and buildings, making your pictures nothing short of amazing. It is also the place to experience some of Cartagena's nightlife. BTW, do not leave Cartagena without heading to Bar Selina; you will thank me later.
3. The Mud Volcano, El Totumo, is a natural spa that you will not forget. The mud has rich minerals which, will be a treat to the skin. So take this opportunity to unwind and destress. I can guarantee that this experience will bring a level of relaxation for which your body will be most grateful. Ohhhhhh, remember to grab a coconut after your dip, this will make this day of R&R even more complete.
4. Casa de la Alba Hotel was just opening when we were leaving Cartagena. Firstly, make sure you sit on the balcony and watch the locals and tourist mix below you. Take some time to take some pictures inside and explore. The hotel is gorgeous. On the night we went, they had a violist who was playing outside. It was simply relaxing and also a good way was to enjoy the historic district of Cartagena. And I can't forget the tapas and drinks, they were simply delicious!
5. End your stay on a Chiva! Listen!!!! Hopping on a Chiva Rumbera would be a highlight of your trip. Chiva is a party bus. Each bus has its mix of music. Additionally, you get the opportunity to see some of the major sites in the city, as the bus drives around the city to some of the most famous sites. Maybe the best point of reference is a "Big Bus" but with a club included. Don't forget to bring your booze. This experience will cost you about $18.
Nonetheless, no matter what you decide to do, I am sure Cartagena will not disappoint. So book that ticket and enjoy Colombia.