When visiting Poland, it is worth going to Kraków (the former capital of Poland), which is famous for its unique architectural monuments such as the Wawel Royal Castle, the Barbican and the Cloth Hall. Near Kraków there are the Royal Salt Mines in Wieliczka and Bochnia. These are one of the oldest rock salt mines in the world and the longest-operating industrial plants – the beginnings of their activity date back to the 13th century. They resemble underground cities, delighting with unique excavations, chapels carved in salt rocks and original sculptures and devices used centuries ago. The Wieliczka Salt Mine has the longest tourist trail in Europe.


Beautiful monuments from the 13th and 15th centuries can be admired in the Old Town of Toruń – burgher tenement houses, the Gothic church of the Assumption of the Blessed Virgin Mary and the cathedral of St. Johns. Particularly noteworthy is a complex of two 15th century tenement house, the so-called "Copernicus House", which currently houses the Nicolaus Copernicus Museum.


Wrocław is home to one of the largest European markets. When visiting this city, it is worth visiting the rotunda of the Panorama of Racławice, displaying the cycloramic painting Battle of Racławice painted in 1893–1894 by a team of painters led by Jan Styka (1858–1925) and Wojciech Kossak (1856–1942). A visit to the Wrocław ZOO and Africarium will also provide unique experiences. A few dozen kilometres from Wrocław, in Wałbrzych, there is the 13th century Książ Castle. It is the third largest castle in Poland (right after the Teutonic Castle in Malbork and the Wawel Royal Castle). 


Castles are the showcase of many Polish municipalities – there are over 400 of them in total. The most impressive include: Krzyżtopór located in the Holy Cross Voivodeship, surrounded by bastion fortifications, the Castle in Moszna, resembling a structure from Disney fairy tales, and the Ogrodzieniec Castle in Podzamcze, where the scenes from the “the Witcher” series (Netflix) were filmed.


Gdańsk, Poznań, Bydgoszcz, Zamość and Kazimierz Dolny are also picturesque cities with centuries of history. Warsaw’s Old Town was almost completely destroyed (approx. 90%) during World War II. After the war it was rebuilt. Currently, it is the only area of the historic Old Town in the world reconstructed on such a large scale, and since 1980 it has been on the UNESCO list of monuments.


An interesting cultural asset of Poland are historic technical facilities – former mines, steelworks, shipyards, bridge structures and hydropower facilities. There are so many of them in Upper Silesia that a special Trail of Technical Monuments was created there.


From the point of view of the history of mathematics and the history of mathematics teaching, the Museum of Przypkowscy in Jędrzejów is particularly interesting – the second in Europe (after the Museum of the History of Science in Oxford) in terms of the number of sundials and astronomical instruments, the Enigma Cipher Centre in Poznań, which comprehensively presents the history of breaking the Enigma cipher and the figures of Polish cryptologists behind this success, and the Jagiellonian University Collegium Maius Museum, which houses, among others, exhibition of calculating machines.


Poland is characterized by exceptionally rich nature. It has 775 km of coastline with the Baltic Sea and several mountain ranges – the Sudetes with the Karkonosze and Table Mountains have a rock structure, the Tatra Mountains are glacial mountains, and the Bieszczady Mountains are one of the most beautiful mountain forest complexes. Poland is also the Land of the Great Masuria Lakes, the Białowieża Forest and many other natural wonders.


More details can be found here: https://www.poland.travel/en/top-atractions/.