Police say a man followed a 19-year-old woman to the Forest Recreation Ground before assaulting and robbing her.
Officers said the attacked happened just after 12.20am on Sunday (December 22).
The man is believed to have followed the teenager away from the city centre along Mansfield Road before dragging her onto the Forest Recreation Ground.
The suspect is described as a slim Asian man aged in his twenties or early thirties.
He has stubble leading to a beard and was described as wearing a dark hoody, black jacket and black jeans.
He fled the scene of the attack on foot in the direction of Nottingham city centre.
Police have appealed for witnesses to come forward.
Detective Inspector Stuart Temple, of Nottinghamshire Police, who is overseeing the investigation, said: "Although incidents of this nature, this is clearly very concerning and will have left the victim absolutely terrified.
"Our priorities now are to ensure that the victim in this case is fully supported and that we trace the man responsible for this attack as soon as possible.
"I would appeal to anyone who was in the Mansfield Road and Forest Recreation Ground areas around the time of this incident to come forward as soon as possible. We are particularly keen to speak to two people who we believe were nearby when the attack happened."
Anyone with information that may help the investigation is asked to contact Nottinghamshire Police on 101, quoting incident 26 of December 22.
Alternatively, Crimestoppers can be contacted anonymously 0800 555 111.
