From Stamps of the World
Plymouth is a city and unitary authority area on the south coast of Devon, England, about 190 miles (310 km) south-west of London. It is situated between the mouths of the rivers Plym to the east and Tamar to the west, where they join Plymouth Sound. Since 1967, the City of Plymouth has included the suburbs of Plympton and Plymstock, which are situated on the east side of the River Plym.
Plymouth was allocated the 620 Numeral in 1840
Read more @ http://en.wikipedia.org/wiki/Plymouth
CROWN HILL (Current name Crownhill) is a district in the north part of the city.
It is known for having an early land defence of Crownhill Fort. This was used in the defense of Plymouth from the land; as well as being an army training base.