İssium

Issium (also known as Beymelek Castle) is a fortification near Demre in Antalya Province, Turkey, dating to the 4th century BC. Built following the plan of nearby Myra castle, it features a north-facing entrance gate and two twin towers with square floor plans. The north tower contains a large cistern with external water supply, and six rectangular olive-pressing basins were found near the north wall. Issium is noted as the only known example of multi-story towers in Lycia.