Just a few miles west of Naples (and easily reached by train), the ancient seaside city of Pozzuoli is probably best known for its bradyseism, a raising and lowering of the Earth’s surface due to underground volcanic activity. Many sites remain from Pozzuoli’s days as an important Roman port, including the Macellum or Temple of Serapis, which for many years was submerged under water. The Flavian Amphitheater (Italy’s third-largest) and the Cathedral of Rione Terra are other popular attractions.

Amsterdam is truly a biker’s city, although pedaling along the labyrinthine streets can get a little chaotic. Stick to walking and you won’t be disappointed. The gentle canals make a perfect backdrop for exploring the Jordaan and Rembrandtplein square. Pop into the Red Light District if you must—if only so you can say you’ve been there. The Anne Frank House is one of the most moving experiences a traveller can have, and the Van Gogh Museum boasts a sensational collection of works.

This region is home to 700 miles of coastline and 90 islands, including Fyn, the third largest island in Denmark. Also known as "Funen," this attractive island of thatched farmhouses, myriad beaches, forests, beaches and grassland offers gorgeous Kattegat and Baltic views. The most popular spot is quirky Odense, birthplace of Hans Christian Andersen, but don't miss Ladby's Viking ship grave, where the remains of a 72-foot longship, burial site of a 10th-century Viking chieftain, have been excavated.

Billund is built on LEGO. The city is home to a LEGO factory, which produces the lion's share of the world's plastic building bricks, and a theme park, LEGOLAND.

There once was an Irish city… You might think "naughty poem" when you hear the word Limerick, but in truth the city inspires so much more than just knowing giggles. Medieval castles and churches give the city a grand feel, while the pubs crawl with lively locals and students who are all craving just one more pint of Guinness. The Hunt Museum boasts a collection of pieces from history's most important and influential artists, while the Foynes Flying Boat Museum will marvel visitors of all ages with its whimsical flying machines.

Corralejo is the largest resort on Fuerteventura. Town Beach, with its calm waters, is best for families, but if you’re into windsurfing or kitesurfing, try breezier Flag Beach or Glass Beach. Diving, fishing, and tours to nearby islands are other popular pursuits.