Apartment of Stefan Żeromski at the Royal Castle, Warsaw

The Royal Castle in Warsaw (Polish: Zamek Królewski w Warszawie) is a royal residence that formerly served throughout the centuries as the official home of Polish monarchs. It is situated in Castle Square, at the entrance to the Warsaw Old Town. The personal offices of the king and the administrative offices of the royal court were located in the Castle from the 16th century until the final partition of Poland in 1795. Initially, the fortified complex served as the residence of the Masovian dukes. In the early 1600s, it was designated to replace Wawel Castle in Kraków as the seat of the King, Parliament (Chamber of Deputies and Senate), and the Polish–Lithuanian Commonwealth. The medieval Gothic structure was remodelled into Italian mannerism by architects Matteo Castelli and Giovanni Battista Trevano. The Baroque easternmost wing was designed by Gaetano Chiaveri and completed in 1747. The Royal Castle witnessed many notable events in Poland's history; the Constitution of 3 May 1791, first of its type in Europe and the world's second-oldest codified national constitution, was drafted here by the Four-Year Parliament. The edifice was redesigned into a neoclassical style following the partitions of Poland. Under the Second Polish Republic (1918–1939), it was the seat of the Polish head of state and president. The Second World War brought complete destruction to the building; in September 1939 it was targeted and ignited by Luftwaffe fighter aircraft, and then detonated by the Nazis after the failed Warsaw Uprising in 1944. In 1965, the surviving wall fragments, cellars, the adjacent Copper-Roof Palace and the Kubicki Arcades were registered as historical monuments. Reconstruction was carried out in the years 1971–1984, during which it regained its original 17th century appearance. In 1980, the Royal Castle and surrounding Old Town became a UNESCO World Heritage Site. Today, it serves as a museum annually visited by over 500,000 people, and one of Warsaw's most recognizable landmarks.

On March 26, 2022, roughly a month after Russia launched a full-scale invasion of Ukraine, U.S. president Joe Biden delivered a speech at the Royal Castle in Warsaw, Poland. During the speech, he framed the military struggle in Ukraine as a fight between autocracy and democracy, and confirmed that under NATO's Article 5, the troops of NATO have "a sacred obligation ... to defend each and every inch of NATO territory with the full force of our collective power". He also praised the "brave and stiff Ukrainian resistance" and "the generosity of ... the Polish people", while making it clear that "the Russian people ... are not our enemy". Near the end of his speech, Biden referred to Russian president Vladimir Putin when he said, "For God's sake, this man cannot remain in power." A number of world leaders expressed disapproval over this statement. The Biden administration later stated that these words had not been part of the prepared speech, and that the administration was not proposing a regime change. This remark overshadowed the rest of Biden's speech. About 11 months later, Biden returned to Warsaw to deliver another speech, in which he reiterated that the current conflict was a fight between democracy and autocracy, and reaffirmed NATO's commitment to Article 5.

Castle Square (Polish: Plac Zamkowy) is a historic square in front of the Royal Castle – the former official residence of Polish monarchs – located in Warsaw, Poland. It is a popular meeting place for tourists and locals. The Square, of somewhat triangular shape, features the landmark Sigismund's Column to the south-west, and is surrounded by historic townhouses. It marks the beginning of the bustling Royal Route extending to the south.

Sigismund's Column (Polish: Kolumna Zygmunta), originally erected in 1644, is located at Castle Square, Warsaw, Poland and is one of Warsaw's most famous landmarks as well as the first secular monument in the form of a column in modern history. The column and statue commemorate King Sigismund III Vasa, who in 1596 had moved Poland's capital from Kraków to Warsaw. On the Corinthian column (which used to be of red marble), 8.5 m high, a sculpture of the King, 2.75-metres high, in archaistic armour is placed. Sigismund's Column now stands at 22 metres and is adorned by four eagles. The king is dressed in armor and carries a cross in one hand and wields a sword in the other.

The Pancer Viaduct was a viaduct in Warsaw joining Castle Square to the Kierbedzia Bridge. It was built in 1846, and demolished in 1944 and was replaced by the Warsaw W-Z Route thoroughfare. It was designed by Felix Pancer and constructed with seven arched vaults made of brick, supported by six pillars and two abutments. Initially, New Downhill Street (ulica Nowy Zjazd) allowed travel from Castle Square to Dobra Street along the viaduct. The street had the shape of the letter "J", reaching the Vistula, and then turning back sharply and steeply towards Dobra Street. After the construction of the Alexander Bridge (commonly called the Kierbedzia Bridge) in 1864, New Downhill Street running over the Pancer Viaduct became the main artery leading from the left-bank of Warsaw to Praga on the right-bank. Tram tracks were on the viaduct from the very beginning. Initially it was a horse-drawn tram line belonging to the railway, which was built to connect the Praga broad gauge line to the standard gauge of the Warsaw-Vienna line. This became the nucleus of the tram network in Warsaw. The original plans for the Kierbedzia Bridge included a rail line to perform this function but the rail part of this plan was abandoned. The viaduct was blown up after the Warsaw Uprising. Retreating German troops blew up the penultimate pillar, causing two adjacent spans to collapse. After the war, there were plans to rebuild the viaduct, but they were abandoned because the significant increase in pedestrian and automobile traffic would have been dangerous for Castle Square and the Old Town. Under the intersection of Krakowskie Przedmieście and Miodowa Street a tunnel was built for the W-Z Route which resulted in the need to reduce the road. The Pancer Viaduct was demolished, and a road was built from the tunnel to the Śląsko-Dąbrowski Bridge (which replaced the demolished Kierbedzia Bridge) on new embankments and viaducts. The only surviving part of the viaduct is a plaque commemorating its construction. It can be found in Castle Square, next to fragments of previous versions of Sigismund's Column. It includes an inscription in Russian and Polish.

Jan Zachwatowicz Monument (Polish: Pomnik Jana Zachwatowicza) is a bronze statue in Warsaw, Poland, located in the Old Town neighbourhood of the Downtown district. It is placed at the Castle Square. The monument is dedicated to Jan Zachwatowicz, a 20th-century architect and conservator-restorer who led the effort of reconstruction of Warsaw following its destruction in the Second World War. It was designed by Karol Badyna and unveiled on 4 March 2021.

St John's Archcathedral (Polish: Archikatedra św. Jana w Warszawie) is a Roman Catholic church within the Old Town precinct in Warsaw, Poland. The Brick Gothic structure stands on Świętojańska Street, adjacent to the Jesuit Church. St John's is one of three major cathedrals in the city, but it is the only temple that also possesses the title of an archcathedral. It is the mother church of the archdiocese of Warsaw and one of Poland's national pantheons. Along with the old city, the church has been listed by UNESCO as a World Heritage Site.

The Leszczyński Residence (Kamienica Leszczynski) - also called the Prażmowski, Pastoriusa, Rautenstrauchów or Dobrycza - is a rococo-classical townhouse at 87 Krakowskie Przedmieście, in Warsaw.

The Aleksander John Tenement (Polish: Kamienica Aleksandra Johna), also known as the Ignacy Nowicki Tenement (Polish: Kamienica Ignacego Nowickiego) is a rococo four-storey tenement house in Warsaw, Poland, located at 89 Kraków Suburb Street, next to the Castle Square, within the Old Town neighbourhood of the Downtown district. The building was originally constructed in the 17th century. It was destroyed in 1939 during the Second World War and rebuilt in 1950. It is included on a heritage list.

St. Anne's Church (Polish: Kościół św. Anny) is a church in the historic center of Warsaw, Poland, adjacent to the Castle Square, at Krakowskie Przedmieście 68. It is one of Poland's most notable churches with a Neoclassical facade. The church ranks among Warsaw's oldest buildings. Over time, it has seen many reconstructions, resulting in its present-day appearance, unchanged since 1788. Currently it is the main church parish of the academic community in Warsaw.

The Jesuit Church (Polish: Kościół Jezuitów), also known as Church of the Gracious Mother of God (Kościół Matki Bożej Łaskawej), is an ornate church within the Old Town precinct in Warsaw, Poland. The temple stands on Świętojańska Street, adjacent to St John's Cathedral, and is one of the most notable mannerist-style churches in Warsaw.

The Library at the Royal Castle is a large building adjacent to the Royal Castle in Warsaw, Poland. It was built between 1779 and 1783 according to design of Dominik Merlini and Jan Chrystian Kamsetzer in order to accommodate the royal collection of books belonging to King Stanisław August Poniatowski, the last King of sovereign Poland. The Library is an elongated building of total dimensions 56 x 9 m, with 15 windows along the entrance hall, and a terrace at the top. The library initially held about 7,500 items, which grew to about 20,000 volumes in 1795. After the King's death in 1798 the whole collection was sold to Tadeusz Czacki, who bequeathed it to the Liceum Krzemienieckie. Following the collapse of the 1830 November Uprising against the Russian occupation, by order of Tsar Nicholas I of Russia, the library was seized and transported to Kiev where it formed the brand new University Library.