Nakuru is Kenya's fourth-largest city and the unofficial capital of the Rift Valley — a busy agricultural hub on the floor of the Great Rift, ringed by volcanoes, soda lakes, and farmland. Most travellers come for one reason: Lake Nakuru National Park, the alkaline lake on the city's southern edge that, in good years, turns pink with millions of flamingos and shelters the densest population of black and white rhinos in Kenya.
The city itself is functional rather than charming — a grid of dukas, matatu stages, and Indian-Kenyan supermarkets that grew up around the railway. But it makes an excellent base. To the north, Menengai Crater is one of the largest calderas in the world; you can drive or walk to the rim for a view across the steaming, forested floor 480 metres below. To the south-east, Hyrax Hill is one of East Africa's most important Neolithic sites, with burial mounds and stone enclosures dating back 3,000 years. Nakuru is also the natural overnight stop for travellers heading west to the Maasai Mara, Kakamega Forest, or Lake Victoria.
Stay a day or two, see the lake at sunrise when the flamingos are densest, hike the crater rim, then move on. The town has decent cafes, a couple of solid hotels, and enough infrastructure to recover before the next leg of a Kenyan trip.