WIKIMAPIA (https://wikimapia.org/34888301/Ruin-field-of-Malviran) : "In 1836, Sir Henry Rawlinson recorded a native's account of great ruins located on both sides of the river Karun within two plains enclosed by arcs of hills on each side (H. Rawlinson, “Notes on a March from Zoháb, at the foot of Zagros, along the mountains to Khúzistán (Susiana), and from thence through the province of Luristan to Kirmánsháh, in the year 1836,” Journal of the Royal Asiatic Society 9 (1839): 83-84). Later Sir Henry Layard visited the Sūsan valley and searched for the ruins, finding limited evidence, consisting of the shrine of Daniel, four piers of a Sasanid bridge over the Karun (apparently within the gorge upstream), and the traces or a city's ruins at Malviran, north of the Karun and "near the river bank" (H. Layard, Early Adventures in Persia, Susiana, and Babylonia, London 1887: 418-428). These traces appear to be even more difficult to distinguish today (apart from some building remains of recent date), although their general location seems certain. The Sasanid city located in this region, and possibly on this very spot, was known as Gilkart or Gilgird (the name is still employed to designate the mountains to the south), and in Greek as Giligerdon. Situated by this city was the infamous "Castle of Oblivion" employed by Sasanid kings to imprison prisoners of state, called Lethe in Greek, and Andmesh or Anowsh-berd in Armenian sources."
WIKIPEDIA (https://en.wikipedia.org/wiki/Castle_of_Oblivion
Claudia A. Ciancaglini, 202, Forteresse de l'Oubli: note étymologique (https://www.academia.edu/3641407/Forteresse_de_lOubli_note_%C3%A9tymologique) (in french)