Fewer tourists visit Tanzania's Tarangire National Park, which makes a case for going in and of itself. Besides being the best place in the northern circuit to see elephants (author Cynthia Moss recorded over 500 individual members in one week here), the large numbers of rotund baobab trees dotting the landscape makes for an overwhelming singular spectacle, giving the 1,003-square-mile park a surreal, prehistoric, even eerie look. Lions, Cape buffalo, other toothy and hoofed animals? Of course, and then some.

A can't miss staple of the safari circuit is Ngorongoro Crater Conservation Area. Sure, it is popular, but don't let the crowds put you off. Ngorongoro is extraordinary not only for its wildlife but for its geology, often dubbed the "Eighth Wonder of the World" because of its aforementioned volcanic credentials. Before it blew its top, this volcano was larger than Mount Kilimanjaro, and now the 12-mile-wide, flat-bottomed crater is a permanent home to about 30,000 large mammals. Heading down the switchbacks of the steep 1,200- to 1,600-foot rim is like entering the world's largest free-roaming zoo. Thousands of flamingos stand stilt legged in the shallow Lake Magadi; Hippo Pool's resident hipsters comically conduct 360-degree roll-arounds to keep their backs moist in the blazing sun; gazillions of gazelles, wildebeests, impalas, and warthogs stand at simultaneous attention while watching a pride of lions saunter in the distance. And if you’re lucky, you'll see Africa's crème de la crème: the endangered black rhino, Ngorongoro’s headliner act.

Kilimanjaro National Park, home to 19,340-foot "Kili," is both a superb wildlife park and probably the easiest, but still lung-suckingly difficult, of the earth's big summits to scale. But as one of the elite Seven Summits—the highest mountains on each continent—it is no walk in the park (try climb in the clouds). Do the math: Three major volcanic peaks, a 37- by 25-mile-wide base that distinguishes it as the highest freestanding mountain in the world with five climate zones, arctic summit conditions surrounding the Great Northern Glacier... . The sucker’s massive and represents a serious undertaking. Still, with over 22,000 climbers a year, Kili is right behind Everest and Annapurnas in popularity as a trekking destination outside of Europe.

If you want to tackle this beast you must have a certified guide, either through your safari agent, from climbing shops in the gateway city of Arusha, or via Park Headquarters in Marangu. You can opt for a bargain-basement Tanzanian guide instead of a trustworthy outfitter, but the possibility of life-threatening altitude sickness makes a case for digging into your pockets to hire a seasoned, well-equipped guide. Best climb times are January to March and June to December. African Adventures (www.africanadventures.com) offers a five-day itinerary via the Maranga Route, the easiest, most popular summit approach. Cost is $800.