Rabana-Merquly was a major regional centre of the Parthian era in the central Zagros highlands. This article explores the hypothesis that the Rabana intramural settlement was in part a ‘sanctuary’ devoted to the ancient Persian water goddess Anahita, based upon extensive architectural augmentations around an ephemeral waterfall, combined with the nearby construction of a probable fire altar. Two jar burials excavated in 2022 inside an adjacent building show this complex also functioned as a mausoleum. Carbon-14 dating of these cremation deposits supports occupation of the site during the second to first centuries B.C. Twin rock reliefs at the entrances to Rabana-Merquly indicate that the fortress was likely associated with the ruling dynasty of Adiabene, a vassal kingdom of the Parthian (or Arsacid) Empire in north-east Mesopotamia. A further link to Natounissarokerta/Natounia on the Kapros is suggested by the iconography of that city's coinage, which features an obverse image of a goddess, potentially a hybrid representation of Anahita-Tyche.