Did you know you can see the Louvre and Notre Dame in Paris for free, get full meals in London for less than $10, and spend the night in a Bavarian castle for $60? How about cruising on the Bosporus in Istanbul for $1? (No, that’s not a typo.)It's cheaper than ever for travelers to visit Europe , thanks in part to plummeting airfares provoked by ultra low-cost carriers — think $69 one-way flights across the Atlantic — and a strong U.S. dollar. But there are plenty of ways to keep the savings going even after you've booked your summer vacation to Paris or Western Ireland.Here are some additional tips on how to shave hundreds of dollars off your next European vacation. Rail Europe has a variety of passes, but for any trip over five hours, opt for a faster, cheaper no-frills airline. Want to drive? Check the aggregators, as well as consolidators like Auto Europe . For a longer trip, a short-term lease of a brand-new Renault or Peugeot will be cheaper — and offer better insurance coverage — than a two-week rental.Consider the myriad of lodging alternatives — farm stays, cottages, private rooms, convents, campgrounds, villa rentals, castles — that are less expensive and more authentic.Spend a pittance on a royal picnic. Just look for the daily markets you’ll find in most towns, and keep your eyes peeled for street stalls and carts selling roasted pork sandwiches and sugary crêpes. Or head to a pub, trattoria, or tapas bar for hearty, traditional dishes costing far less than at a restaurant. When you do dine at a temple of haute cuisine, go at lunch, not dinner: you usually get the same menu for less.The best things in Europe can often be free. Those grandiose churches that showcase frescoes, stained glass, and architecture by Michelangelo and Matisse? Free. London’s top museums like the British Museum, Tate Modern, and others? No charge. Also, most European tourist offices offer discount passes for public transportation and sightseeing (a notable exception: the largely useless Venice Card).Sharpen your bargaining skills for Europe’s street markets, and you’ll return with more interesting souvenirs (and colorful stories) than the tourists who stuck to the overpriced tchotchke shops.Trimming your budget doesn’t mean sacrificing the quality of your trip. In fact, the less you spend, the less insulated you are from the local culture. Staying in a thatched Irish farmhouse, perusing old masters in Rome, or snacking your way through Spanish specialties aren’t just the tricks of the frugal traveler: they’re the stuff dream vacations are made of.