Just an hour's boat trip away from Cartagena lie the magnificent Rosario Islands, which belong to Colombia's only underwater natural park (Rosario and San Bernardo Corals National Natural Park). Abundant marine wildlife (including over 50 species of corals) and some of Colombia's best beaches draw in many in search of relaxation and active pursuits such as snorkelling and diving. Isla Grande is best for kayaking through unique mangrove forests and seeing the phosphorescent plankton light up the waters of a brackish lake at night, while Playa Blanca is Cartagena's most spectacular white-sand beach (also reachable by land). It should be said that the company you choose to tour with has the potential to make or break the experience. Low cost tours can mean multiple intermediate stops en route to your destination, as well as unpleasant surprises such as no transfer back to your hotel. Try and choose a trusted company with consistently good reviews, or opt for a private tour. Mind that seas may be rough at certain times of the year, particularly in December and January, when tours on smaller boats may even become dangerous.

Former property of the famous Brazilian landscape architect and artist Roberto Burle Marx. The residence and its 100-acre gardens house an extensive exhibition synthesizing the artist's genius, ideas and innovation. A large number of plant species, their diversity and a revolutionary mix of nature and art make this collection one of the most important and entrancing in the world.

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.

The Romanian Athenaeum concert hall is home to the superb Filarmonica George Enescu and the hub of Bucharest’s musical activity. Exquisite mosaics and historical frescoes adorn the 19th-century circular building, which hosts impressive orchestral concerts and other performances. You can visit the ornate, domed, circular building without attending a concert, too.