The southern Serengeti is characterised by rolling tree-studded grassy plains, a habitat which makes up one third of the park's entire area. The most accessible part of the Serengeti National Park, it can get busy here in peak season but it's classic savannah country with great game viewing all year round.

From January to April, the newly-watered plains provide fresh grazing for the tens of thousands of wildebeest, zebra and gazelles that have left the Masai Mara. It's here that the main calving season takes place and predators - especially the big cats - are highly concentrated in this section of the park.

The Serengeti's centrally located Seronera River Valley marks the boundary between the grassy plains of the south and the wooded hills of the north. As a result, the area is home to wildlife from both habitats making the central Serengeti one of the richest ecosystems in the park and game viewing is good throughout the year.

The wildebeest and zebra herds are in the region from around December to May and your chances of seeing predators are high, especially when the herds are dropping their young between February and March. Lions and cheetah are common, and leopards are often seen in the valley where the lack of trees makes it relatively easy to spot them.

Tucked away between the Serengeti National Park, Lake Natron and the Ngorongoro Conservation Area is Loliondo, a community-based conservation area that provides grazing for the migrating herds between December and April. Many wildebeest drop their calves in the Loliondo region between February and March, attracting large numbers of predators.

It's an area of diverse habitats which means a wide range of wildlife, and the fact that it lies outside of the Serengeti National Park means that not only are there very few visitors but lodges in the Loliondo concession are allowed to conduct walking safaris and night drives, activities not permitted in the park itself.

Following the line of the Grumeti River, the Serengeti's Western Corridor pushes the park's borders all the way to Lake Victoria. Be there between May and July when the 40-kilometre long caravan of wildebeest, zebra and gazelles arrives on the banks of the Grumeti to begin the perilous river crossings, running the gauntlet of the river's notoriously giant crocodiles.

The crocodiles feast off the crossing herds and give those lucky enough to witness the encounter one of the most remarkable wildlife sightings in the world - book your accommodation early to ensure front-row seats.

June and July are the months to be in the Grumeti Reserves, a 162 000 hectare private concession area bordering the Western Serengeti. An area of classic savannah and open woodland, the wildebeest not only have to cross the muddy, crocodile-infested waters of the Grumeti to continue their northward migration but they have to avoid the large numbers of lion, hyena and cheetah in the area too.

Grumeti is good for wildlife all year round. Even in September and October large wildebeest herds remain alongside healthy numbers of topi, zebra, Thomson's gazelle and eland while in November southbound wildebeest, returning from the Masai Mara in Kenya, move back into the reserves after the season's first rains.

The Grumeti region is also a great bird watching area with over 400 recorded species and the riverine forest is a good place to spot colobus monkeys. And since Grumeti is a private reserve, visitors at the area's lodges have the opportunity to go on guided nature walks and night drives, activities not allowed in the Serengeti National Park.

Far less crowded than the rest of the Serengeti, the north of the park is characterised by green rolling hills and thickly vegetated granite outcrops and offers visitors the highlights of the Serengeti without the crowds.

Game is not as prolific as the central and southern regions of the Serengeti but from around August to October the migrating herds move through the area to cross the Mara River on their way north to the Masai Mara. This is the time to visit the northern Serengeti: dramatic scenes ensue as tens of thousands of animals plunge into the river in a desperate attempt to reach the other side before the river's enormous crocodiles home in on them - book your accommodation well in advance to guarantee ringside seats.