As there are no options stated, I will provide some relevant activities and attractions that could be found in Cartagena.
In the old part of Cartagena, you can visit the Church of San Pedro Claver (400 years old) and the Plaza de Bolivar which is placed dedicated to Simón Bolivar (he helped Latin America to separate from Spain).
In the Modern part, you can go to the beaches (12 miles of beaches) and enjoy the tropical weather. You can visit Boca Grande where you can find cafes, bookshops, shops, galleries and other places to have fun and enjoy.