Police were called to Rising Sun Country Park just after 4pm on Monday, March 28, after a member of the public had found a woman in distress.
Officers attended and a 63-year-old woman said she had been approached by a man, forced to the ground and raped before he made off.
Enquiries are ongoing and the victim is receiving support from specially trained officers.
Detective Chief Inspector Shelley Hudson said: "We understand this may cause concern within the community and public safety is absolutely paramount.
"We do have an increased police presence in the area to provide reassurance and for people to come forward with information or concerns as the investigation continues.
"The victim is being fully supported and extensive enquiries are underway."
Anyone with information or notice any suspicious behaviour is encouraged to contact police via the Northumbria Police website or contact 101 quoting NP-20220328-0700 or Crimestoppers on 0800 555 111.