Karatza lagoon is located in the regional unit of Rodopi, between the lagoons of Xirolimni and Alyki, and very close to Arogi village and the homonymous beach. It is part of the National Park of Eastern Macedonia - Thrace, as one of the so-called 'Rhodope lagoons'.

It is a shallow lagoon with salty swamps and a narrow coastal sandy beach. It is surrounded by bare, partially cultivated hills with small islands and flat muddy terrain. In the southeastern part of the lagoon, there is a fishing station and camping area.

Karatza lagoon is one of the most important habitats for birds in Greece, with species that breed, migrate and winter in it, while it is suitable as a place for bird watching and walking, any time of year.