Ngorongoro Crater

Ngorongoro Crater is the collapsed caldera of an ancient volcano in the highlands between the Rift Valley and the Serengeti plains. Its walls drop about 600 metres from the rim to a floor of roughly 260 square kilometres. Down there you'll find open grassland, the soda water of Lake Magadi, reed swamps, the Ngoitokitok spring and the yellow fever trees of the Lerai forest.

The crater is the centre of the wider Ngorongoro Conservation Area, a UNESCO World Heritage Site. It's a multiple-use area rather than a national park, so on the highland roads you'll pass Maasai herders moving their cattle between villages and grazing.

The walls keep a dense population of animals close together, and most of them stay all year. Buffalo, wildebeest and zebra graze the grassland in large numbers. Lion and spotted hyena are common, and golden jackal trot along the tracks.

The crater is also one of the most reliable places in Tanzania to see black rhino. Sightings are usually at a distance across open ground, so bring binoculars.

Hippo wallow in the pools near the picnic sites. Elephant, mostly old bulls with heavy tusks, browse in the Lerai forest and the swamps. Flamingo gather on Lake Magadi when the water level suits them. What you won't see on the floor is giraffe, which surprises a lot of first-time visitors.

Because the wildlife is resident, the crater works in every month. What changes is the weather and the number of vehicles.

• June to October: dry and clear, with the easiest game viewing and the most vehicles. Nights on the rim are cold.
• November to March: green season, with the short rains usually falling in November and December. The floor turns green, migrant birds arrive and, outside the holidays, there's less traffic.
• April and May: the long rains. Mist often sits on the rim in the morning, the roads get slippery and some lodges close, but you'll share the floor with far fewer people.

One full game drive on the floor is enough for most travellers. Plan at least one night on the highlands so you can be at the gate early. Two nights give you time for a guided walk on the rim, a stop at Olduvai Gorge on the way west, or a dawn visit to Lake Eyasi.

Ngorongoro is the hinge of the northern circuit. It sits between Tarangire and Lake Manyara to the east and the Serengeti to the west, so nearly every route passes through.

On a short trip it's the highlight. The 3-day Tarangire and Ngorongoro safari pairs it with Tarangire's elephants. On longer routes such as the 5-day classic Tanzania safari, you'll usually drive the crater on the way to or from the Serengeti. It's a core stop on any classic wildlife safari.

• Altitude and temperature: the rim sits at roughly 2,300 metres and the floor at about 1,700 metres. Rim mornings and nights are cold, especially from June to August, so pack a warm fleece, a jacket and a hat.
• Where you stay: comfort-level lodges usually sit in the farmland and coffee country around Karatu, under an hour from the crater gate. On a luxury itinerary you may stay on the rim itself, looking straight down at the floor.
• Time on the floor: park rules limit how long each vehicle may spend on the floor, and nobody stays there overnight. Most guides go down soon after the gates open.
• Picnics: kites are bold at the picnic sites and will snatch food from your hand. Eat inside the vehicle.
• Roads: the descent and ascent roads are steep and narrow, and they're one-way in places.