The area is crossed by numerous permanent streams, draining from the Nyambenes and flowing in parallel between tounges of lava, south eastwards towards the Tana River. 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. There are several prominent inselbergs of basement rock, notably Mughwango and Leopard rock.
A section of the park has been designated as a wilderness area in which are no roads. The park is part of the domain made famous by the writings of Joy Adamson.