There are in fact many marshes, which produce a special microclimate.
Lower Silesia (Polish: Dolny Śląsk; Czech: Dolní Slezsko, Latin: Silesia Inferior; German: Niederschlesien; Silesian German: Niederschläsing; Silesian: Dolny Ślůnsk) is the northwestern part of the historical and geographical region of Silesia; Upper Silesia is to the southeast. Throughout its history Lower Silesia has been under the control of the medieval Kingdom of Poland, the Kingdom of Bohemia and the Austrian Habsburg Monarchy from 1526..
In 1742 nearly all of the region was annexed by the Kingdom of Prussia and became part of the German Empire in 1871, except for a small part which formed the southern part of the Lower Silesian Duchy of Nysa and had been incorporated into Austrian Silesia in 1742.After 1945 the main part of the former Prussian Province of Lower Silesia fell to the Republic of Poland, while a smaller part west of the Oder-Neisse line remained within East GermanyŹródło: https://en.wikipedia.org/wiki/Lower_SilesiaIn the north-west is the Baltic seacoast, which extends from the Bay of Pomerania to the Gulf of Gdańsk. This coast is marked by several spits, coastal lakes (former bays that have been cut off from the sea), and dunes. The largely straight coastline is indented by the Szczecin Lagoon, the Bay of Puck, and the Vistula Lagoon.
About geographyPoland's territory extends across several geographical regions, between latitudes 49° and 55° N, and longitudes 14° and 25° E.
The centre and parts of the north lie within the North European Plain. Rising above these lowlands is a geographical region comprising the four hilly districts of moraines and moraine-dammed lakes formed during and after the Pleistocene ice age.These lake districts are the Pomeranian Lake District, the Greater Polish Lake District, the Kashubian Lake District, and the Masurian Lake District.The Masurian Lake District is the largest of the four and covers much of north-eastern Poland.
The lake districts form part of the Baltic Ridge, a series of moraine belts along the southern shore of the Baltic Sea.