The remains of the fortress can be visited
Kadifekale Castle

On a hill in İzmir, Turkey, the Kadifekale Fortress offers views over the city and the Gulf of İzmir.
History+
The origins of the fortress date back to the time of Lysimachus, a successor of Alexander the Great, who had the first defensive walls built around 306 BC. This was part of the refoundation of Smyrna on Mount Pagos to accommodate the growing population. A legend tells that Alexander the Great himself was urged by goddesses in a dream to found the city at this very spot. In the 14th century, the fortress experienced a divided history when it was captured by the Aydinids, while the port city was held by the Genoese. The walls visible today date from the medieval period, although some sources suggest Hellenic masonry fragments beneath the existing structures.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://en.wikipedia.org/wiki/File:Kadifekale_IzmirTurkey_EUnluBlogspot.jpg
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 38.4138, 27.1468