The area is almost wholly mountainous, although there are some fertile valleys on the Shropshire side. The highest point is Mole Sych (2,713 ft). Its main rivers are the River Severn and the River Dovey. Lake Vyrnwy is a reservoir supplying Liverpool. The main towns are Llanfyllin, Machynlleth, Montgomery, Newtown and Welshpool. The main industries are agriculture (mainly hill farming) and tourism.
The area is now administered as part of Powys.
Places of special interest: