Plympton, or Plympton Maurice or Plympton St Maurice or Plympton St Mary or Plympton Erle, in south-western Devon, is a populous, north-eastern suburb of the city of Plymouth of which it officially became part, along with Plymstock, in 1967. It was an ancient stannary town: an important trading centre in the past for locally mined tin, and a former seaport (before the River Plym silted up and trade moved down the river to Plymouth).