Nico Ditch is a six-mile (9.7 km) long linear earthwork between Ashton-under-Lyne and Stretford in Greater Manchester, England. It was dug as a defensive fortification, or possibly a boundary marker, between the 5th and 11th century.The ditch is still visible in short sections, such as a 330-yard (300 m) stretch in Denton Golf Course.