Gündüz, Serkan2024-09-272024-09-272022-04-091057-2414https://doi.org/10.1080/10572414.2021.2021485https://www.tandfonline.com/doi/full/10.1080/10572414.2021.2021485https://hdl.handle.net/11452/45350In the Byzantine period, Helenopolis was one of the most important landing places on the southern coast of the Nicomedia Gulf, located, according to historical sources, on the main sea route from Constantinople to Nicaea. Although historical sources mention a pier in Dilburnu, there is no record of a lighthouse on the cape. This article provides details of two harbour structures that were detected and documented during a recent survey. In order to understand the position of the pier at some distance from the shore, the change in the coastline over a period of 80 years was examined.enSoli-pompeiopolisTowerHelenopolisLighthousePierJustinianCoastal changeSocial sciencesArchaeologyArticle00078164900000136137450210.1080/10572414.2021.20214851095-9270