NEW YORK — Sure, air travel is a hassle. And no, the U.S. dollar doesn't go very far in Paris or London. But none of that is keeping Americans away from Europe.

Nearly 13 million Americans visited Europe in 2006, a 4 percent increase from the previous year, according to preliminary data from the U.S. Commerce Department's Office of Travel & Tourism Industries. The European Travel Commission expects those numbers will increase another 2 or 3 percent this year.

Here are some of the trends, events and destinations shaping those trips.

SHORT TRIPS AND BYWAYS: Now that you need a passport just to visit the Caribbean, some Americans — especially those already on the East Coast — are opting to spend a few more hours in the air to take a long weekend in Western Europe, according to Conrad Van Tiggelen, chairman of the European Travel Commission, www.visiteurope.com. "Traditional destinations like Paris and London are really going through the roof for short breaks," he said.

Another trend is "combining the known and the unknown" by visiting landmarks in a major city, then heading off to the countryside, said Van Tiggelen.

"Seeing the Eiffel Tower is still a great thrill, as is going to the Vatican. But there is a subset of more sophisticated travelers yearning to see a more authentic side of Europe," said Pauline Frommer, the travel writer and editor.

In Italy, a program called agriturismo allows travelers to "stay in a farmhouse set up for tourism and take part in the daily life and the making of particular products like cheese and wine," according to Cosmo Frasca, spokesman for the Italian Government Tourist Board in New York. In Amsterdam, take a ferry across the Amstel River, rent a bike and "after 10 minutes, you're in 17th- and 18th-century villages," said Van Tiggelen, who is also the Netherlands tourism director.

Americans are also increasingly taking "experiential vacations," said Peter Frank, editor of Concierge.com. "They want to engage in an activity — windsurfing in Croatia, hiking the pilgrim's trail to Santiago de Compostela (in Spain) or taking a cookery class in Italy."

For city visits, here's a money-saving tip: Stay in an apartment instead of a hotel. The new "Pauline Frommer's London" guidebook lists agencies that can set "you up in a room in someone's apartment for 20 pounds a night," with a private bathroom, said Frommer. "It makes Europe affordable again."