Slains Castle in Aberdeenshire was cordoned off after the discovery was reported to police at around 9.15am on Sunday.
The death of the woman, who was aged in her 50s, is being treated as unexplained.
Police said inquiries are continuing and the cordon has since been removed.
There are not thought to be any suspicious circumstances.
Police Scotland later said the woman was 54.
The force said that as with all sudden deaths, a report will be submitted to the procurator fiscal.