(MONEY Magazine) – Europe's shoulder season--when the weather is good but the summer hordes haven't yet arrived--is upon us, so good deals are available through May and even into June. Until May 31, for example, Visa cardholders get 50% discounts (60% on weekends) at most of the 179 Radisson SAS hotels in Europe. Call 800-333-3333.

Two can cruise for the price of one on the posh Cunard Vistafjord, now refurbished after a 1997 fire. Starting April 27, Vantage Deluxe World Travel (888-652-7103) offers 16-day sails of the Mediterranean, Black and Aegean seas for $6,070 a couple, including round-trip air fare from 75 U.S. cities and two nights' onshore accommodations. Meanwhile, Royal Olympic Cruises (800-872-6400) is discounting its 11-day Mediterranean Odyssey cruise by 30%, to $1,600 a person. Round-trip air fare from New York City or Boston and two nights in Athens are included.

Starting April 23, a new service called Ameribus (800-922-0322) offers 30 days of unlimited "hop-on, hop-off" travel on one of its three regional bus routes in California, Florida and the Northeast for only $129. The California circuit, for example, encompasses Los Angeles, San Simeon, Monterey, San Francisco, Yosemite National Park and Las Vegas.

Stop and smell the tulips in Holland. Martinair Holland is offering a seven-day trip for $859 per person through May 31. (You'd pay about $1,700 if you booked the trip yourself.) That covers air fare, hotel stays in Amsterdam and the Hague, and entry to the famed Keukenhof Gardens. Call 800-790-4682 by May 17.

Hoping to set up a tent in a national park this summer? It's best to reserve a campsite now--and starting this year, the National Park Service is taking reservations up to five months in advance on the Web (reservations.nps.gov) as well as by phone (800-365-2267).

--VANESSA RICHARDSON