Erwood sits on the A470 road between Builth Wells and Brecon in Powys, South Wales. The Clettwr Brook flows through the village to join the Wye, which runs past Erwood.
Interestingly, the former weekly magazine Punch has its roots here. Henry Mayhew was staying in the village and whilst sitting in the local inn one day, he came up with the idea for a humorous newspaper. Punch ran from 1841 to 1992 and had a second run from 1996 to 2002.