Arnö

Arnö is a locality situated in Nyköping Municipality, Södermanland County, Sweden with 3,871 inhabitants in 2010.

==Geography== Arnö is situated on a peninsula on the south side of the bay, with Nyköping on the north side. Locally, Arnö is considered a part of main Nyköping, but is designated a locality due to the mile-long stretch between Nyköping and itself. The populated area was mainly built in the 1970s and has become a southern suburb of Nyköping, being in walking distance from the city. Expansion is planned eastwards towards the beach of Örstigsnäs. It is also located relatively near the town of Oxelösund, with its outer premises forming the municipal line.