Enclosed within a protective wall reaching up to 20 metres in width, the Ciudad Amurallada (or Walled City) is Cartagena's old beating heart. Packed with well-preserved colonial buildings, it's a pleasure to stroll through; its streets of colourful low-rise merchant homes marked by iconic balconies are now mostly walked by either tourists or students who attend classes at the University of Cartagena during the day and linger for meals and nightlife after school is out. Cafes in Plaza Aduana and Plaza Santo Domingo teem with patrons, forging an incredibly jovial atmosphere; the districts of San Diego and El Centro are two not to be missed. There is plenty of food and shopping to be had, with a mixed bag of world-class restaurants and street food hawkers and the incredibly photogenic palenqueras — women dressed in vibrantly coloured clothing selling fruit in the streets — images of whom have become emblematic of Colombia as a travel destination.

If snorkelling and/or scuba diving sounds like your idea of fun, Cartagena is the place to indulge. Waters of the Caribbean washing over this part of the coast hold abundant marine life, including multiple varieties of tropical fish and corals, and the several underwater shipwreck sites make for exciting diving. The archipelagos of Rosario and San Bernardo are both excellent for either.

Housed in a beautifully restored Jesuit school building from 1612, the Museo Naval del Caribe covers in some detail the 500 years of Cartagena's maritime history. You'll find sunken ships, cannons, ship's bells, muskets, and other treasures here. The descriptions are in Spanish, so it's a good idea to get a guided tour.