SOUTH AMERICA & ANTARCTICA CRUISES

In the early 20th century, Buenos Aires, Argentina, gained immense wealth when it began shipping its pampas-raised beef around the world. It quickly entered the club of great world cities, and a slew of attractions and architectural jewels soon arose. Since that time, the capital has experienced huge swings in economic and political fortune. But Buenos Aires continues to fascinate and entertain sightseeing visitors, both for its chaotic energy and for its sheer urban beauty. Thankfully, the Belle Époque grandeur and enormous tracts of greenery remain. Any list of things to do in Buenos Aires would begin with its many walkable neighborhoods.

Dramatic, fantastical, otherworldly—this is the end of the world, for real. Positioned at the southernmost tip of Argentina, this memorable port town is cradled between the pristine—and towering—Martial Mountains and accessed by the picturesque Beagle Channel (which was named for Darwin’s famed vessel). Ushuaia, a maze of streets lined with low-slung buildings, is the capital of the Tierra del Fuego region, which is best described as a spectacular collection of superlative natural wonders. It’s a veritable kaleidoscope of glittering glaciers, snowcapped mountains, dense forests, sparkling lakes and windswept plains spread across an archipelago of rugged islands.

If ever a city were a model for boom and bust, it would be Manaus. Like in America’s Old West, great fortunes were amassed in no time here and vanished just as quickly during the late-19th-century boom years of rubber production. These days, Manaus is busy again: A swank new soccer stadium was added for the 2014 World Cup, and a spectacular cable-stayed bridge opened in 2011 across the Rio Negro. The Ponta Negra suburb has modern high-rises, beaches that rival those on the sea and buzzing restaurants that serve Amazonian specialties like pirarucu fish and acai berries.

If Punta Arenas exudes an "edge of the world" air, it's not without reason. This windblown city near Chile's southernmost tip sits on the Strait of Magellan, which itself is positioned squarely between the Atlantic and Pacific oceans. The city has played—and continues to play—an important role in geographic, political and economic affairs in South America's so-called Southern Cone, which is formed by Chile and neighboring Argentina. From penguin spotting on Isla Magdalena and kayaking the Strait of Magellan to visiting area farms and then indulging in surf-and-turf specialties (here meaning fresh seafood and asado, or Chilean barbecue) at local restaurants, Punta Arenas is worth a stopover.

Some cities need no introduction, and even fewer cities live up to their reputation the way Rio de Janeiro does, in both the best sense—how visitors experience sheer exhilaration being there—and the harsh reality of its social and economic strains. It’s all about stopping at corner juice bars to enjoy fresh tropical drinks named for fruit you’ve never even heard of, and people-watching along the Copacabana and Ipanema boardwalks. You might take the plunge into Maracaña Stadium to watch a crazy match between crosstown rivals Flamengo and Fluminense or jump on a bike to discover some of Rio’s far-flung and vastly diverse districts.