ARGENTINA/URUGUAY The Delta Porteños like to escape to where the Río Paraná flows into the Río de la Plata, 17 miles northwest of Buenos Aires. There, they fish, sail, kayak, and idle their weekends away. With the recent opening of the 15-cabana La Pascuala Delta Lodge (54-11/4728-1253; www.lapascuala.com; doubles from $175) and, farther upstream on the Uruguay side, the Four Seasons Resort Carmelo (598-542/9000; www.fourseasons.com; bungalows from $150, suites from $180), travelers to B.A. can do the same. Blue Star (54-11/4731-6000; www.bluestarlines.net; five-hour cruise $45) just began running luxury cruises through the Delta; soon, boats will go to Montevideo and head up the Río de la Plata to Paysandú, where Uruguay's little-known (for now, anyway) hot springs are found.
BRAZIL Pipa Despite its obvious attractions—10-plus miles of sugary beaches, an abundance of tidy pousadas, surprisingly sophisticated restaurants—this village 53 miles south of Natal was put on the map just 10 years ago by championship-level surfers. Before they arrived, the cobblestoned town and its coastline, which skims stretches of virgin Atlantic forest, were populated only by fishing families who had dwelled there for generations. Book a room at the teak-and-tile Toca da Coruja Pousada (55-84/246-2226; www.tocadacoruja.com.br; doubles from $90), and contact Pipa Tour (55-84/246-2234; www.pipatour.com.br) for boat, buggy, Land Rover, and fishing trips.
ECUADOR La Costa With a network of recently completed roads and a rapidly developing tourist infrastructure, Ecuador's 937-mile coast is just about ready for prime time. The country's Pacific shoreline has tranquil hideouts, such as the thatch-and-stucco Hosteria Atamari (593-4/278-0430; doubles from $128); quiet beaches (the ones around Canoa are the widest); wildlife sanctuaries (from June through September, whales migrate along Machalilla National Park, south of the Manabí province); and countless opportunities to enjoy the superlative Ecuadorean shrimp.
BRAZIL Chapada Diamantina Recently dubbed Brazil's "Taj Mahal of adventure tourism," this 376,000-acre national park in the heart of Bahia is a mountainous playground of waterfalls, caves, pools, cacti, orchids, and, rumor has it, the occasional UFO. Catch a flight from São Paulo to Lençóis, drive to Portal Lençóis (55-75/334-1233; doubles from $72), and let Andrenalina Turismo (55-75/334-1261; www.geocities.com/andrenalina2000) guide you through.
BRAZIL Serra da Bocaina The word bocaina translates to "high road," and this 272-acre national park midway between São Paulo and Rio is a hiker's highway to heaven. To traverse the 50-mile Trilha do Ouro (or "gold trail"—the paths were used in the 18th century to transport gold from Minas Gerais to the coast), contact MW Trekking (55-12/577-1178; three-day hikes from $288, including gear and meals). Or just wander at leisure around the eight-room Pousada Vale dos Veados (55-12/577-1102; www.hoteisdabocaina.com.br; doubles from $90), in the middle of the park.
PERU Colca Valley Although not far from the heavily trod Machu Picchu/Lake Titicaca/Nazca tourist circuit, Colca Valley has remained blessedly unscathed—despite its snowcapped volcanoes, white-knuckle rapids, pre-Incan ruins, colonial villages, and a depth twice that of the Grand Canyon. Stay way down in the crevasse at the eco-sensitive El Parador del Colca (51-1/242-3000; doubles from $70), a seven-room inn recently acquired by Orient-Express and marked for expansion.
PERU Kuelap Ruins At the mountaintop citadel of the pre-Inca Chachapoyas civilization, in north-central Peru between the Andes and the Amazon, visitors can trek on foot or horseback for miles, on trails that pass through ancient settlements, burial grounds, and battlefields. Tropical Nature Travel (877/888-1770; www.tropicalnaturetravel.com; tours from $690 per person) has four-, five-, and seven-day walking trips, from the city of Chiclayo.
CHILE Chiloé Rough waters and wild weather have historically limited travel to this 40-island archipelago off the coast of Patagonia, but with a bridge in the works that will link the Isla Grande to the mainland, Chilotesare preparing for a new era that will showcase their misty forests, penguin colonies, and more than 16 UNESCO-protected churches. Family-owned farmhouses are opening their doors to overnighters, and tour companies such as Austral Adventures (56-65/625-977; www.austral-adventures.com; four-day trips from $399) have updated their nature-oriented kayaking trips through the emerald islands.
BOLIVIA Las Yungas Mountain Valley The single-lane, cliff-hugging road from La Cumbre (an hour northeast of La Paz) to Coroico (the heart of semitropical Las Yungas) drops more than 11,800 feet in 40 miles. This makes for a hair-raising bike trip—try Gravity Assisted Mountain Biking (800/345-4453; guided tours from $50, including rental)—or a Hail Mary-worthy ride by car. Next year, the road will be widened, thereby increasing two-wheel traffic. Set up camp in a room with a mountain view at the spare but comfortable Hotel Esmeralda (591-2/213-6017; www.hotelesmeralda.com; doubles from $20).
ARGENTINA Salta and Jujuy Provinces Adding to the allure of the tropical valleys, windswept highlands, and dusty pueblitos of Argentina's northwest corner are three standout properties: the riverfront El Manantial del Silencio (54-388/490-8080; www.newage-hotels.com; doubles from $65) in Purmamarca; the vineyard-flanked Bodega La Rosa (54-386/842-1201; www.micheltorino.com.ar; doubles from $135) in Chafayate; and the adobe El Molino de Cachi Adentro (54-11/4314-3390; www.elmolinodecachi.com; doubles from $80) in the Calchaqui Valley desert. Bonus: Gauchos outnumber tourists—at least for now. —Connie McCabe