Stretching from the snow-capped heights of Kilimanjaro, undulating through Africa's central Great Rift Valley to the shores of Lake Victoria, Tanzania's well-trod Northern Circuit is the country's most popular safari destination, and justifiably so. Blessed with an incredible array of the continent's highlights -- world's highest free-standing mountain, largest intact volcanic caldera, oldest hominid footprint, and largest migration of game on Earth -- the Northern Circuit is (and should be) a given on any East African itinerary.
Kilimanjaro aside, the Serengeti and Ngorongoro Crater are the circuit's most famous destinations, but with careful planning, you can fit in a great deal more, untrammeled by the large number of visitors this region inevitably attracts, despite the relatively high costs of traveling here.
Within easy striking distance of Arusha, unofficial safari capital of the Northern Circuit, Tarangire National Park is not only one of Tanzania's most beautiful reserves, with baobab-studded yellow plains giving way to lush green swamps, but during the dry season, when large herds of game migrate to the perennial waters of the Tarangire River, your game experiences will rival those of the Serengeti.
The next stop (or penultimate, depending on which direction you're traveling) is Lake Manyara, a shallow soda lake at the base of Gregory Rift, the cliffs of which mark the steep ascent to the volcanic highlands of Ngorongoro. With the country's densest concentration of elephants, all well habituated to the presence of vehicles and humans, close-up encounters with Lake Manyara's resident pachyderms are guaranteed, as are stunning vistas the farther south you travel, culminating in the viewpoints above the Maji Moti hot springs, where pink clouds of flamingos hover above a white soda shoreline and bands of gray and blue meet a cerulean sky. If this inspires a yen for more awe-inspiring landscapes, set aside 2 days and head north to Lake Natron, breeding site for East Africa's flamingos, its caustic waters shadowed by the brooding presence of Ol Doinyo L'Engai. The last in the line of the Rift Valley's active volcanoes, this is the Maasai's sacred "Mountain of God," as compelling as Kilimanjaro in its bleak majesty.
More jaw-dropping landscapes await as you ascend the 800m (2,624-ft.) Gregory Rift to enter the Ngorongoro Conservation Area, an area of some 8,300 sq. km (3,237 sq. miles) stretching from the cool Karatu Highlands to the Serengeti plains in the west. The highlight of the Ngorongoro Conservation Area is the crater after which it is named, but this is also the traditional heartland of the Maasai, and traversing the region you will encounter that quintessential African sight: lone warrior-herders swathed in red, spear and stick held aloft as they stride before their cattle across the vast and empty plains. Also falling within the Conservation Area is Olduvai Gorge, where Mary Leakey unearthed footsteps made by the earliest proto-humans around 3.6 million years ago, and archaeologists continue to uncover clues to the origins of ancient man.
Finally, it is the Serengeti that will leave you truly dumbstruck: Home to what is regularly vaunted as the greatest wildlife spectacle on planet Earth, this World Heritage Site -- umbrella-topped acacias and vast herds in a sea of yellow grass -- is the Africa of your dreams, its timeless beauty reassuring in an otherwise rapidly changing world.