335km (208 miles) from Arusha, 245km (152 miles) from Tarangire, 175km (109 miles) from Lake Manyara, 90km (56 miles) from Ngorongoro

Take it from an African: The Serengeti is the greatest game park on the continent. It's not just the wildlife, though the sight of more than two million animals moving across the plains is regularly cited as the greatest wildlife spectacle on Earth. Nor is it the size, although, at 14,763 sq. km (5,758 sq. miles), the park is almost the size of Hawaii, and the greater ecosystem -- an area encompassing the Ngorongoro Conservation Area; Maswa Game Reserve; Loliondo, Grumeti, and Ikorongo Controlled Areas; and Maasai Mara National Reserve in Kenya -- is double that.

It was the Maasai who called it Siringitu (The Place Where the Land Moves on Forever), and it is precisely this sense of vastness that will blow you away. The sheer expanse of the short-grass plains, like a yellow sea, is broken only by occasional rocky outcrops and elegant acacia trees, like giant bonsais sculpted by some invisible hand. And above it all is "the high noble arc of the cloudless African sky," as the American hunter-turned-conservationist Stewart Edward White so lyrically put it in 1913. The first man to encounter the great Migration moving through the Serengeti, White was clearly bowled over: "Never have I seen anything like that game. It covered every hill, standing in the openings, strolling in and out among groves, singly, or in little groups. It did not matter in which direction I looked, there it was, as abundant one place as another. Nor did it matter how far I went, over how many hills I walked, how many wide prospects I examined, it was always the same. I moved among those hordes of unsophisticated beasts as a lord of Eden would have moved."

The Migration is central to the Serengeti's appeal. It's a virtually continual movement of some 1.3 million wildebeest, 200,000 zebra, 300,000 Thomson's gazelle, and thousands of eland, kongoni, and topi, all following a millennia-old instinct to seek new pasture as the life-sustaining rains that come twice a year sweep across the greater Serengeti. Contrary to the popularly held promise that the Migration is an "event" that takes place at a certain time of year, it is a slow, vaguely counterclockwise cycle, starting (or ending) near the Ndutu and Masek soda lakes that lie in the volcanic plains west of the Ngorongoro Crater. Following the short rains that usually drench the southern plains during November and December, turning yellowed plains into green pastures brimming with nutrient-rich grass, breezes filled with moisture call the wildebeest south. Already heavy with calf, the wildebeest arrive in their thousands during December, ready for the annual population explosion that occurs in January, when up to 8,000 calves are born daily. Predators are in close attendance, patiently awaiting any opportunity to sink their teeth into this abundance of vulnerable flesh -- a great time to experience the thrill (or, for the squeamish, horror) of the primal brutality of nature, in which the weak and vulnerable are essential to the survival of the hunter.

As the Ndutu plains start to dry and the soda lakes turn salty, the animals start their 1,000km (620-mile) annual pilgrimage, and million-strong herds begin to move northwest in anticipation of the heavy rains that will soon transform the central Serengeti. April to mid-May, thundershowers sweep the park, sustaining the herds as they move through the central Seronera plains and up through the Western Corridor, plunging into the crocodile-infested waters of the Grumeti around June, while others veer northeast, walking via Lobo through to the Mara River. Regardless of where they find themselves, the nodding wildebeest columns -- some as long as 40km (25 miles) -- are all headed north, reaching the waters of the Mara by September or October, traditionally the driest months for the Serengeti National Park. Here they remain until they sense the coming rains and head south to the breeding grounds of the southern plains, timing their arrival with its transformation into lush pasture.

Aside from the migrating herds, the park sustains stable populations of many other species, and you will certainly encounter giraffe, warthog, olive baboon, vervet monkey, and buffalo, as well as elephant (though the latter are not as commonly encountered as at Tarangire or Lake Manyara). More important, for most, at least, is the large population of predators. An estimated 2,000 lions alone prowl within the park, many of them territorial and well habituated to human presence; aside from encountering them during the day, you will almost certainly hear them roar at night -- a powerful and thrilling sound that can reverberate across the plains 5km (3 miles) or more. Hyenas and jackals are also plentiful. Cheetahs, mostly encountered on the plains, are more elusive; leopard, while more plentiful in number, are even more so. Moru Kopjes is where you will encounter the park's small rhino population; hopefully, with plans afoot to boost their numbers, these great prehistoric mammals will become more prevalent. Serengeti is also an ornithologist's paradise, with the chance of sighting more than 500 species, from the world's largest bird -- the ostrich, with its pink legs during mating season -- to some of the strangest (look out for the secretary bird, its officious strut and old-fashioned elegance marking it as a character from a Dickens novel).

Given this abundance, it is hardly surprising that Tanzania's oldest game park is also the most popular (though visitor numbers are still nowhere near those in Masai Mara). Despite its popularity, it is still possible to enjoy a more exclusive safari in Africa's finest game park, but choosing where and when you go has never been more important.