The Phalombe Plain slopes gently towards Lake Chilwa to the northeast, and separates the highlands from the taller Mulanje Massif to the east.
Streams originating in the highlands drain west, south, and southeast towards the Shire River, or northeast into the closed basin of Lake Chilwa.
[1] The highlands have a cooler climate and more rainfall than the surrounding lowlands, and are home to distinct forests, woodlands, and grasslands that make up the South Malawi montane forest-grassland mosaic.
[2] The northernmost portion of the plateau includes a line of hills – Chinduzi, Mongolowe, Chaone, and Chikala – that extend 40 km east and west.
In the middle of the 19th century, Yao people migrated eastwards from the northern Mozambican coast, and established chiefdoms in the highlands – Malemia (Domasi), Mlumbe (Zomba), Kawinga (Chikala), Mpama (Chiradzulu), and Kapeni and Somba (in Blantyre District).
[5] With encouragement and assistance from David Livingstone during his second Zambesi expedition, in 1861 Bishop Charles Mackenzie of the Universities' Mission to Central Africa set up a missionary station at Magomero, near Zomba in the highlands.
Johnston abolished the slave trade, and allowed British missionaries and settlers to lay claim to large tracts of the highlands.