Mrzeżyno[mʐɛˈʐɨnɔ] (German: Deep, or Treptower Deep, after 1930 often Regamünde) is a village with a fishing seaport in Gryfice County. This is also a health resort with a lots of pensions, campsites and spa. It is located near the estuary of the Rega river. The village has a popular beach. Every year in July and August, Mrzeżyno is visited by many Polish and German tourists. The right riverside is more developed than left, where there is only one settlement. The population numbers 1,727(2009). The village is situated by a special area of the conservation of nature according to the European Union's program Natura 2000. It lies approximately 10 kilometres (6 mi) north of Trzebiatów, 27 km (17 mi) north of Gryfice, and 94 km (58 mi) north-east of the regional capital Szczecin.
In the 1920s Lyonel Feininger often came to the Treptower Deep to paint and reside.