The English writer Samuel Johnson famously said, "You find no man, at all intellectual, who is willing to leave London. No, Sir, when a man is tired of London, he is tired of life; for there is in London all that life can afford."

The best time to visit London is in the spring when the temperatures are mild and the city's parks are green and blooming. However, late spring along with summer is also prime tourist season, and hotel and flight prices reflect the surge. You're more likely to find airfare and accommodation deals in the fall and winter though you'll also encounter chilly temperatures.

The best way to get around London is the rapid-transit London Underground, or what locals call "the Tube." You can even take the Tube from Heathrow Airport (LHR) one of the world's busiest airports into the city center. This widespread and efficient system stretches throughout London and beyond, and it is relatively easy to navigate. Buying an Oyster card will further simplify your travel since it can be used on the Underground system, as well as on city buses and other forms of transportation.

The small island of Bora Bora (just 6 miles long and more than 2 miles wide) overflows with beauty. Dormant volcanoes rise up at its center and fan out into lush jungle before spilling into an aquamarine lagoon. In fact, author James Michener, who wrote "Tales of the South Pacific," called Bora Bora "the most beautiful island in the world."

The best times to go to Bora Bora are November and April. These short shoulder seasons offer fine weather with temperatures in the mid-70s to mid-80s. High season runs from May to October when rain showers are isolated and the number of tourists swells. Low season stretches from December to March when the weather is wet and visitors become mosquito bait.

The best way to get around Bora Bora is by bike, especially when you consider that the entire island only takes four hours to traverse. Rental cars are another option, but they cost significantly more than a rental bicycle. The local bus system, Le Truck, is notoriously unpredictable and taxis are quite expensive.

Barcelona contains both the authentically historic and the wildly bizarre. From the tree-lined Las Ramblas to the narrow alleys of Barri Gòtic; from the beachside nightclubs to the city's dozens of sacred churches and cathedrals, this city by the sea seems to attract all types: the family, the adventurer, the couple, the backpacker, the culture lover and more with an almost overwhelming variety of things to do.

The best time to visit the Barcelona is from May to June when balmy temperatures in the low to mid 70s mesh with a flurry of festivals that trumpet the advent of summer. The actual summertime is sticky with humidity locals leave their beloved city in droves to catch a breeze somewhere else.

The best way to get around Barcelona is by Metro. A handful of numbered and color-coded lines weave throughout the city, making stops near many of the city's most popular attractions, but unfortunately not at the airport. To travel from Barcelona Airport (BCN), you'll need to catch a taxi, ride a bus or rent a car. Speaking of city buses, be aware that ever-present traffic jams make commuting via bus rather time-consuming.

The City of Light draws millions of visitors every year with its unforgettable ambiance. Of course, the divine cuisine and vast art collections deserve some of the credit as well. The gentle River Seine rambles through the city, flanked by stately museums, centuries-old churches, and blocks of Rococo and Neoclassic-design architecture, further enhanced by charming trees and glowing streetlamps.

The best time to visit Paris is from June to August, when the weather is just about parfait (perfect). Average highs are in the mid 70s and there are long days of sunshine. Unfortunately, summer is also the most crowded time and the most expensive. For a significant drop in tourism, plan a trip in the fall or spring.

The best way to get around Paris is on foot the elegant arrondissements are practically made for pedestrians. Still, Paris is very big, so you should take the efficient metro system (Metropolitain) to travel long distances. The Regie Autonome des Transports Parisiens or RATP system, which runs the metro, also offers several bus routes around the city.