Just north of Cancun, this seaside resort community is a far cry from the spring-break crowd. Bordered on one side by the Mexican Caribbean and the other by a wetlands wildlife preserve, the vibe in Playa Mujeres is one of laid-back luxury in a natural, untouched landscape. Unlike many other such tranquil places, Playa Mujeres is not a pain to get to. It's an easy ride from Cancun airport.

Key Largo's spectacular Sandspur and Caloosa Beaches are a part of protected area Bahia Honda. This divine duo of sandy beaches, with their coconut palms and year-round warm waters, offer marvellous swimming, snorkelling and kayaking in their calm waters. Sandspur is especially popular with families.

How often do you get the chance to walk through a tunnel of lava? Created by the flowing and cooling process of liquid magma, the underground lava tubes of Santa Cruz are simply breathtaking. The most popular is the Tunnel of Love, so named for the heart-shaped hole in the ceiling. Cool down with a splash in the fresh waters of Puerto Ayora, snorkel at Tortuga Bay or the mangrove-lined Garrapatero Beach and get friendly with the giant natives at the El Chato Tortoise Reserve.

Boasting a historical dockyard housing Henry VIII’s Mary Rose and Lord Nelson’s HMS Victory, Portsmouth has maritime heritage written all over it. Museums aside, the city still lives and breathes the sea—best exemplified in its nautical spirit, cobbled historic district, and sail-shaped Spinnaker Tower viewpoint.