Just an hour's boat trip away from Cartagena lie the magnificent Rosario Islands, which belong to Colombia's only underwater natural park (the 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.

The fortification, first erected in the 13th century, still stands today - and relatively well-preserved, at that. An on-site museum tells the brief history of the fort, but its main draw is, perhaps, the unbeatable view over the Medina and the sea surface - things may get a bit crowded at sunset.

Espoo’s lovely islands are within easy reach from Helsinki. In summer, a ferry service will take you to outdoor recreation islands such as Iso Vasikkasaari with an island restaurant. In the mainland, enjoy Espoo’s 40 km long Waterfront Walkway. There are places to stop for a bite to eat and drink, and you can try swimming, fishing, kayaking, paddleboarding, a RIB ride or wakeboarding. During cold winters the frozen sea offers the perfect setting for skiing, snowshoe walking and ice fishing.