The body remains at the scene which is being preserved for a technical examination.
The 14-year-old was last seen in the nearby Catherine's Park on Monday evening, and gardai are treating her death as suspicious.
Anastasia, who was from Leixlip, Co Kildare, had been missing for three days.
A full investigation is underway at a derelict site in Lucan in Dublin, after a body was found during a search for a missing teenager.
Body of teenage girl has been discovered in Dublin
Gardaí are awaiting the results of a post mortem to determine the course of the investigation.
Gardaí say they are investigating all the circumstances of her death, but say it is being treated as suspicious. They are investigating if Anastasia was with someone when she was last seen.
'They also want the public's assistance and privacy as well as they have another child in the house so we have to be careful around that'.
"She was a particularly striking girl; quite tall for her age and very well known in the locality because of that", Supt Gordon said.
According to RTE News, it is believed the body was discovered in a disused building, and the State Pathologist's Office and Garda Forensic Bureau have been notified.