Meru National Park is a savanna National Park, 85 kilometers east of Meru town in the northeastern lowlands below the Nyambeni hills. The wetter north-western sector (rainfall c.700 milimeters per year) is hilly, with rich volcanic soils. The land flattens towards the east, where grey alluvial volcanic soils appear. This area is crossed by numerous permanent streams, draining from the Nyambenis and flowing in parallel between tongues of lava, southeastwards towards the Tana river.

There are several prominent inselbergs of basement rock, notably Mughwango and Leopard Rock. The vegetation on the ridges is Combretum-wooded grassland, dominated by Combretum apiculatum. This grade into Acacia wooded grassland to the east, with Acacia tortilis and A. senegal on the rocky ridges, in riverine thickets and dotted over open country, and Doum palms Hyphaene coriacea in the numerous swampy areas near the rivers. Chloris gayana is the dominant grass in many places, with Cyperus species in the swamps.

The south and south-east (rainfall c.300 milimeters per year) is an open, semi-arid plain with red lateritic soil. This area is covered with rather uniform Acacia - Commiphora bushland, a hot, dense, thorny and inhospitable habitat. As well as the many streams that cross it, the park is bounded by three large rivers: the Tana to the south, the Ura to the south-west and the Rojeweru to the east. Riverine trees include the palms Raphia farinifera and Phoenix reclinata, Ficus sycomorus, Newtonia hildebrandtii, Acacia elatior and A. robusta. Along the Tana river is found the Tana River Poplar Populus ilicifolia. Meru is part of a complex of protected areas along the Tana river that includes the adjacent Bisanadi and North Kitui National Reserves (to the east and south, respectively), Kora National Park and Rahole National Reserve. These areas are better protected on paper than on the ground, however, and their birdlife (though generally little known) appears less rich than Meru's.

The park's avifauna is generally diverse, with around 300 bird species recorded. The threatened Turdoides hindei, which has a very restricted range in central Kenya, has recently been recorded, near Kindani and Nyati Camps in the south-west part of the park. Regionally threatened species include Ephippiorhynchus senegalensis (known to breed), Polemaetus bellicosus (status unknown), Podica senegalensis, Scotopelia peli and Phoeniculus granti.

Meru is an excellent birding destination. It has several northern Kenya specials, including the impressive Somali ostrich, Boran cisticola and vulturine guineafowl. The noisy yellow-necked spurfowl is very common and the sought-after Hinde's babbler can sometimes be spotted as well. Others include; African finfoot, , Bat hawk, Black-faced sandgrouse, Boran cisticola, Buff-crested bustard, Golden palm weaver,Golden-breasted starling,Grant's wood-hoopoe, Hinde's pied babbler, Martial eagle, Northern pied babbler, Palm-nut vulture, Pel's fishing-owl, Rufous chatterer, Saddle-billed stork, Somali bee-eater, Somali ostrich, Taita fiscal, Vulturine guineafowl, Yellow-necked spurfowl.

Meru offers good bird watching throughout the year, but the best time is from November to April when the migrants from Europe and North Africa are present. This coincides with the breeding season when many species are nesting. Although good for birding, April tends to be very wet and is a less productive time for wildlife viewing.