Silesia Walls are a line of three (or sometimes fewer) parallel earthen ramparts and ditches that run through Lower Silesia

Lower Silesia

Lower Silesia ; 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 Poland

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

, by the towns Szprotawa

Szprotawa

Szprotawa is a town in Poland, in Lubusz Voivodeship, in Żagań County. It has 12,648 inhabitants .- History :The first information about the terrains of today's Szprotawa comes at 1000 from the chronicle of bishop Thietmar of Merseburg, who accompanied the emperor Otto III on pilgrimage to the...

 and Kożuchów

Kozuchów

Kożuchów is a town in Lubusz Voivodeship, Poland.- External links :*...

. The walls are about 2.5 metres tall and, at their widest, 47 metres. They run for about 30 kilometres. It is hypothesized by Maciej Boryna of the Muzeum Ziemi Szprotawskiej

Muzeum Ziemi Szprotawskiej

Muzeum Ziemi Szprotawskiej , established 2000 by Towarzystwo Bory Dolnośląskie . It is the local center for historical and archeological research pertaining to the old Szprotawa District, for the towns of Szprotawa, Małomice, Przemków and Niegosławice....

 that the Silesia Walls were the southwest border

Border

Borders define geographic boundaries of political entities or legal jurisdictions, such as governments, sovereign states, federated states and other subnational entities. Some borders—such as a state's internal administrative borders, or inter-state borders within the Schengen Area—are open and...

 of the Duchy of Głogów and built in 1413-1467. It is possible that rather than being military in nature the wall was designed to reduce smuggling.