World Youth Day 2011: Paris, Lourdes & Madrid

This city was made for walking. Stroll grand boulevards with sweeping views of the city, pristine parks with trees planted in perfect rows, and narrow streets crowded with vendors selling flowers, pastries and cheese. Then head to the Île de la Cité, a small island in the Seine, to see Notre Dame Cathedral. Look up at the great stone buttresses, grotesque gargoyles, and massive stained-glass windows.

Visit one of the original college towns. Since the Sorbonne’s founding in the 1100s, the Left Bank has attracted not only intellectuals but also the cafés, bookstores, and cinemas that tend to accompany them. It’s also attracted its fair share of famous residents – a plaque marks one of Hemingway’s apartments on rue du Cardinal-Lemoine, and the imposing neoclassical Panthéon holds the tombs of Voltaire, Rousseau, Victor Hugo, and Marie Curie.

The world's largest art museum, the Louvre is housed in a medieval fortress-turned-castle so grand it's worth a tour itself. You walk through the 71-foot glass pyramid designed by I.M. Pei and added in 1989, and step into another world-one with carved ceilings, deep-set windows, and so many architectural details, you could spend a week just admiring the rooms. But check out the art on the walls. The Mona Lisa is here, as well as the Venus de Milo and Winged Victory (the headless statue, circa 200 BC, discovered at Samothrace). The Louvre has seven different departments of paintings, prints, drawings, sculptures and antiquities. Don't miss the Egyptian collection, complete with creepy sarcophagi, or the collection of Greek ceramics, one of the largest in the world. (Please note the Louvre is closed on Tuesdays.)

What's that huge white arch at the end of the Champs-Élysées? The Arc de Triomphe, commissioned by Napoleon in 1806 after his victory at Austerlitz. Your licensed local guide will elaborate on this, and other Parisian landmarks. See some of the most famous sites, including the ornate, 19th-century Opera, the Presidential residence, the ultra-chic shops of the Rue du Faubourg St-Honoré, and the gardens of the Tuileries. You'll pass the Place de la Concorde, where in the center you’ll find the Obelisk of Luxor, a gift from Egypt in 1836, and the Place Vendôme, a huge square surrounded by 17th-century buildings. Spot chic locals (and tons of tourists) strolling the Champs-Élysées. Look up at the iron girders of the Eiffel Tower, built for the 1889 World's Fair to commemorate the centenary of the French Revolution. See Les Invalides (a refuge for war wounded), the École Militaire (Napoleon's alma mater), and the Conciergerie (the prison where Marie Antoinette was kept during the French Revolution).

Kick off the experience of a lifetime with an opening mass presided over by the archbishop of Madrid in Cibeles Square. During this week, you will have the opportunity to participate in catechesis session with bishops from all over the world, as well as attend concerts, exhibitions, displays organized by the World Youth Day Event Committee. For more details, please visit http://www.madrid11.com/en/schedule.

A castle fit for a king! This stone fortification rises up imposingly from a rocky crag in the old city of Segovia. See its towering round turrets, spindly spires, luxurious throne room and fully stocked armory.

Tapas purportedly originated when bartenders set a small plate ("tapa") over patrons' glasses of sherry and wine to keep the flies out. The bartenders starting piling the plate with cold cuts, olives, or salad, and the bite-size snack was born. (We're unsure how they kept the flies out of the cold-cuts... maybe that's how the sandwich was invented?) Over time these working-class snacks have become more elaborate, with each region adding its own specialties and cooking techniques to create unique tastes and combinations.