The last Roman City on the eastern side of the Danubian Limes is Halmyris. It is a City-port which plays a primordially military role, situated at the link between the fluvial and the marine environment. The fortress is famous for its location at the foot of the legendary Peuce Island. Halmyris benefits from important natural resources from two environments with distinct characteristics: marine (Halmyris Bay) and freshwater (Danube Delta). When the city was founded, the St. George arm was the most important navigation artery of Danube. Therefore, the penetration upstream was monitored strictly by the City-port of Halmyris (customs). This study emphasizes on the existence of natural favorable premises for the city of Halmyris and it attempts to revitalize thematic tourism. The assessment of paleoenvironment evolution and present conservation stage has been achieved to improve the risk management plan.