Grays (or Grays Thurrock) is the largest town in the borough and unitary authority of Thurrock in Essex and one of the Thurrock's traditional (Church of England) parishes. The town is approximately 20 miles (32 km) to the east of London on the north bank of the River Thames, and 2 miles (3.2 km) east of the M25 motorway. Its economy is linked to Port of London industries, its own offices, retail and Lakeside, West Thurrock.