Nicolaus Copernicus already visited the Warmian chapter in Olsztyn in 1511. One of the many tasks assigned to him by the chapter was to perform the duties of administrator of its assets. Because of all these tasks, the scholar lived in the Capitular Castle in Olsztyn in 1516- 1519 and 1520-1521. His duties included settlement of depopulated villages, as a result of war activities, with new settlers, which was associated with numerous field trips. The testimony of these activities is the manuscript entitled " Locationes mansorum desertorum", which contained records of visits to 43 Warmian villages.

At the request of the new Warmian bishop Fabian Luzjański in 1517, Copernicus wrote a dissertation on the reform of money, which he developed two years later in the treatise " Minting of Coin". In 1520, he prepared the castle and city to defend against the expected Teutonic attack. This brought the desired effect in January 1521, when the assault of the Teutonic unit on the city walls in the vicinity of Furta Młyńska was repelled. Over the next twenty years, the astronomer visited the city on the Łyna many times.

Olsztyn obtained city rights in 1353, then the construction of the castle was completed. Other monuments with a Gothic origin in the city are: the co-cathedral of St. James the Apostle, church of St. Wawrzyniec, Old Town Hall, High Gate and fragments of the city walls. In addition, among others: the Jerusalem Chapel from the 16th century, seven churches and chapels from the 19th and early 20th centuries and the funeral home of the Jewish community.

The construction of the castle of the Warmian chapter began around 1348. The northern wing was completed in the second half of the 14th century. The southern one, with a 30-meter round tower, was recontrusted in the mid-15th century. In the mid-18th century, the eastern, late Baroque wing was built. Today, the Museum of Warmia and Mazury is located in this castle [http://muzeum.olsztyn.pl/], in which you can see, among other things, an exhibition dedicated to Copernicus and the cloister drawn by him on the wall, as well as the partly preserved astronomical table (705 cm by 140 cm). It served to depict the Sun’s apparent movement in the days around the spring and autumn equinox.

In the park of the castle there is the bust of Copernicus which was presented in 1916, made by Berlin sculptor Johannes Götz. At the entrance to the castle a second Copernicus monument was placed in in 2003. It was created by Urszula Szmyt. It has the form of a bench - you can sit on it with the astronomer and pose for photos.

On the 500th anniversary of the scientist's birth (1973), a planetarium was opened in Olsztyn [http://planetarium.olsztyn.pl/]. During the screenings presented in it, viewers go on virtual space travelexplorations, learn the secrets of the starry sky, astronomical phenomena and secrets of nature. Near this facility, an astronomical observatory was set up in the former water tower.

For guests seeking active leisure, the city offers, among others summer attractions of the Ukiel Sports and Recreation Center [http://www.osir.olsztyn.pl/pl/ukiel], located by the lake of the same name, and throughout the year – the city offers the Aquasfera Aquatic Recreation and Sports Center [http://www.osir.olsztyn.pl/pl/aquasfera]. You can also go kayaking on the Łyna or on any one of the smaller rivers around Olsztyn.