During National Park Week, the park service will waive admission fees to all of its parks, including Yellowstone. (Jonathan Newton/The Washington Post)

This week’s best travel bargains around the globe.

Land

The National Park Service, which celebrates its centennial this year, is waiving admission fees during National Park Week. On April 16-24, nearly 130 parks will offer free entrance, including Yellowstone and Grand Teton (normally $50 for a seven-day pass for the pair), Everglades ($20 per car; valid for a week) and Shenandoah ($20 per car; good for a week). Info: nps.gov/planyourvisit/fee-free-parks-state.htm.

Amtrak has a sale on Northeast train travel this spring, with 25 percent off fares. From Washington, one-way fares on the Northeast Regional start at $39 to Philadelphia, $49 to New York and $79 to Boston. Book by April 30, at least 14 days in advance. By comparison, typical fare to New York starts at $69. In addition, on the Acela Express, save 25 percent on any destination between New Haven, Conn., and Washington when you book at least 14 days in advance for Saturday and select weeknight service. Info: amtrak.com.

Petit St. Vincent Resort, a 115-acre private island property in the southern Caribbean, is offering seven nights for the price of five for stays June 1-Aug. 15. A one-bedroom cottage, including meals, is $5,500 per couple for seven nights, a savings of $2,200. Taxes and service charges are 20 percent extra. The deal also includes drinks and boat transfers from Union Island. Book by calling 800-654-9326. Promo details: petitstvincent.com/rates/seven-for-five-summer-offer.html.

Sea

American Queen Steamboat Company has a last-minute special on four cruises in April between Portland, Ore., and Clarkston, Wash. The cruises, which include a one-night hotel stay and seven nights aboard the 223-passenger American Empress riverboat, start at $1,999 per person double, a savings of at least $1,600. You must pay in full at the time of booking. Info: 888-749-5280, americanqueensteamboatcompany.com.

With the Come Back New sale, Princess Cruises is offering shipboard credits of up to $600 on more than 300 voyages. Plus, book a suite and receive a free spa treatment. Amount of credit is based on trip length and cabin category. For example, a cruise lasting six to nine days earns $150 for two passengers in an interior or oceanview stateroom and $300 for guests in a balcony, mini-suite or suite. Passengers in a full-size suite can choose between a La Thérapie hydra-lift facial and a 50-minute Swedish massage. Sample itinerary: A six-day western Caribbean cruise departing Fort Lauderdale, Fla., on Nov. 27 starts at $559 per person double and $199 for the third and fourth passengers in an interior cabin. Add $110 in taxes and fees. Book by May 12 and use promo code N3A. Info: 800-774-6237, princess.com.

Air

Southwest has launched a sale on nonstop flights. For example, fly from Reagan National to Orlando for $134 round trip, including taxes. Other airlines are matching, but fares typically start at about $189. Restrictions vary by destination. For travel to Florida, for example, fly on Tuesdays and Wednesdays April 12-June 15 and Aug. 23-Nov. 2. Fourteen-day advance purchase applies. Book by April 14 at southwest.com.

Package

World Spree is offering a Best of Peru & Amazon tour starting at $3,699 per person double. The trip includes round-trip airfare from New York to Lima; three flights in Peru; 10 nights in five hotels, including two nights at the Inkaterra Reserva Amazonica lodge; 20 meals; ground transportation, including a train ride to Machu Picchu; tours with entrance fees; airport transfers; and taxes. Priced separately, the trip costs at least $4,100. For lowest rate, depart Aug. 30-Nov. 22. Book at least three weeks in advance. Info: 866-652-5656, worldspree.com.

— Carol Sottili, Andrea Sachs

Submit travel deals to whatsthedeal@washpost.com. Prices were verified at press time Thursday, but deals sell out and availability is not guaranteed. Some restrictions may apply.