Wisłoujście Fortress is the oldest coastal fortress located in Gdańsk, on the banks of the Martwa Wisła River, at the mouth of the old Vistula River, which flows into the Gulf of Gdańsk. This impressive defensive structure protected ships en route to the port of Gdańsk. It also served as a lighthouse, a mooring place for the Polish fleet, and a prison.

Książ Castle, located in Wałbrzych, Lower Silesia, Poland, is one of the country's largest castles and a significant historical and cultural monument. The castle has a long and complex history, dating back to the 13th century. Over the centuries, it has undergone numerous expansions and renovations. The castle has served many different roles, acting as a defensive fortress, a royal residence, and a cultural center.

Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of 312,696 km2 (120,733 sq mi). Poland has a population of over 38 million. Warsaw is the nation's capital and largest metropolis. Other major cities include Kraków, Łódź, Wrocław, Poznań, Gdańsk, and Szczecin.

Malbork Castle, also known as the Castle of the Teutonic Order in Malbork, is a medieval fortress located in the town of Malbork in northern Poland. It is one of the most significant and well-preserved castles in Europe, recognized as a UNESCO World Heritage Site.

Wawel Royal Castle is a castle residency located in central Kraków, Poland. Built at the behest of King Casimir III the Great, it consists of a number of structures situated around the Italian-styled main courtyard. The castle, being one of the largest in Poland, represents nearly all European architectural styles of medieval, renaissance and baroque periods.