Sandal Castle, about two miles away from Heath, is currently closed as part of the investigation.
Police were called at about 1.50am this morning to a report that a 32-year-old woman had been seriously sexually assaulted in a pub car park on Heath by a man.
Detective Inspector Andy Welbourne at Wakefield CID, said: “Initial enquiries are ongoing into a report of a serious sexual assault in Heath and police forensic officers have been carrying out enquiries there and at Sandal Castle where we have a linked crime scene.
“The victim is being spoken with by specially trained officers as investigations continue.”