BME Black Mountains East of Grwyne Fawr valley

BMW Black Mountains West of Grwyne Fawr valley

BMS Black Mountains South of River Usk

BBC Talybont to A470

BBF A470 to A4067, except BBY

BBM West of A4067, including Usk Reservoir

BBY East of A4067, South of Ystradfellte

OXO For 'minority' area walks