About 3 - 4 million years ago, curing the massive eruptions of Ngorongoro, Sadiman and Kerimasi volcanoes, a thick rain of ash settled over the plains, creating a rock-hard top coat, known as hard-pan. Although richly fertile, it is too tough to be broken by tree roots, leaving the landscape to the shallow rooted grasses, packed with nutritious minerals which act as a magnet to grazers such as wildebeest, zebra, impala and Thomson's gazelles.

From Nabbi Hill Gate, the grasslands stretch around you in all directions. There will be animals here at any time of year, but from October to May, the area will be teeming with life, including wildebeest, zebra, warthogs, topi, hartebeest, impala, Thomson's and Grant's gazelles, kori bustards, secretary birds and ostrich. Hyenas and jackals prowl nearby, while vultures circling overhead may indicate the position of a kill.

Lions, almost the exact colour of the grass in the dry season, are more easily visible at some of the rocky kopjes, granite inselbergs scattered across the landscape. The Moru Kopjes are favourites amongst many big cats including lion, leopard, serval and caracal, and you may even find elephant in the area. Simba Kopjes are frequently used for sunbathing by the lions after which they are named. You may also see baboon, giraffe and a good variety of birds in the area. Gol Kopjes are popular with cheetah, while the Maasai Kopjes again attract lion and formidably large cobras.

At the centre of the park, the Seronera River Valley is one of the richest wildlife habitats in the region, not only providing a valuable water source, but also making the boundary between the grassy plains and the wooded hills to the north, attracting animals and birds belonging to both environments. In addition to plains animals, the woodlands are favoured by baboons and monkeys, buffalo, giraffe, eland, bushbuck and dik-dik. Waterbuck and reedbuck hang out along the river banks, overlooked by leopard who love to laze away the heat of the day in the shady sausage trees. The river provides a home for hippos and crocodiles, while many of the park's estimated 517 species of bird can be found in the area. Seronera is also home to the Visitor Centre and Serengeti Balloon Safaris.

Heading north, the Lobo area becomes more rugged, with craggy hills covered by scrubby bush and open woodland, favoured by buffalo and elephant. In the gallery forest along the watercourses, look out for rare gingery Patas monkeys and brightly coloured turaccos. Antelope living in the rocky hills include mountain reedbuck, oribi and the grey bush duiker.

The Western Corridor sticks out like a panhandle, following the line of the Grumeti River and taking the borders of the Serengeti the whole way to Lake Victoria. A central range of hills is flanked on either side by large areas of plains, their sticky black cotton soil bursting into flower during the rains. It may look spectacular but is a nightmare for drivers, and the area is best visited in the dry months (June to October), when the non-migratory animals cluster along the river. Eland and roan antelope both live in the area, while the wooded river banks are home to black-and-white colobus monkey and some spectacularly large crocodiles (up to 6 metres/20 ft in length),which spring into a feeding frenzy when the wildebeest come through, usually in May to June.

Bird lovers - apart from vultures that tend to follow the migration, the Serengeti's 517 identified bird species stay within their range. Some are migrants, found in the Serengeti only during the European winder months from October to April. The Ostrich, which is the largest bird and numbers some 4,300 in the Serengeti, are present all year round. So are the colourful Lilac-breasted rollers, the Kori Bustard which is the largest flying bird in Africa, Secretary birds and the Superb Starling that is ever-present at the Naabi Hill entrance gater. There are also magnificently coloured Fischer's lovebirds with their orange-red faces, parrot-like beaks and bright green, almost translucent plumage.

The Agama lizards, the males coloured red and blue during mating, are to be found around Seronera and on the other rock kopjes as are diminutive hyrax. Nile monitor lizards are found along waterways where they prey on crocodile eggs.

Butterflies excist in abundance, particularly after the rains. Damp areas and stream banks are places butterflies most frequently drink and concentrations are to be found at puddles containing animal urine and dung.