The Trap Grounds lie between the Oxford canal and the railway line, immediately south of the Frenchay Road canal bridge. An information board marks the entrance to the site, at the start of a track called Frog Lane. The Trap Grounds consists of three acres of reed bed (a rare fragment of a type of wetland habitat once common around Oxford) and four acres of scrubland — formerly waste-ground, and now a rich mosaic of wildlife habitats.