The most well-known structure in Budapest is perhaps the Hungarian Parliament, or Országház in Hungarian. It serves as the hub for the Hungarian parliament as well as other institutions like the parliamentary library. Its main entrance is on Kossuth Square, in the city's V district close to the Danube River.

Imre Steindl, who went blind a few months before the building's dedication, designed it, and it was built between 1885 and 1904 under his direction. The Hungarian National Assembly meets in this structure, which is also the second-largest parliament in the world after Romania. It is the biggest structure in the entire nation. It is neo-Gothic in style, albeit with some oddities.

Imre Steindl created the structure, which has a heavily Baroque-influenced floor plan and is almost neo-Gothic in its elements, in the spirit of historicizing eclecticism. This imposing structure was constructed in the Viennese neo-Gothic style, under the influence of Friedrich von Schmidt. Schmidt erected the Our Lady of Victory Church in Vienna in the Rhine Gothic style, and Imre Steindl greatly referenced Schmidt's dome while creating the dome for the Budapest Parliament. The inaugural session of the National Assembly was convened in the newly constructed parliamentary building on June 8, 1896, marking the 2,000th anniversary of the establishment of the Hungarian state.

The use of purely domestic building materials was a requirement for erecting the Parliament. The eight marble monoliths next to the main stairway are an exception. On October 12th, 1885, the first excavation was conducted on the site of Kossuth Lajos Square. During construction, an average of 7,000 workers moved 176,000 cubic metres of earth over the course of 17 years. There were 40 million bricks, 500,000 ornamental stones, and 40 kg of gold utilised.

Despite being opened in 1894, the structure wasn't finished until 1902, by which time both houses of parliament had migrated. Up to 1904, construction was ongoing.

The Hungarian People's Republic came to an end on October 23, 1989, when Mátyás Szrös, the nation's acting president, declared the Third Republic of Hungary from a balcony.

With a floor area of 17,745 square metres and a volume of 473,000 cubic metres, the structure has a total of 691 rooms and is 268 m long, 123 m broad, and its dome rises to 96 m high. The main façade faces the Danube, however Kossuth Lajos Square serves as the formal entry to the building.

Gold and marble are used to embellish the inside. The symmetrical structure of the building houses a bicameral parliament. The offices of the Prime Minister are located in the north wing, while those of the President of the Republic of Hungary are located in the south wing.

On either side of the exterior staircase, there are two lion statues. The columns are 4 tonnes each and are composed of red granite that is 6 metres high. Allegorical works by Károly Lotz, including "Apotheosis of Legislation" and "Glorification of Hungary," may be seen on the ceiling.

There are various statues of Hungarian rulers in the central hall, where the dome can be viewed from the inside, including St. Stephen and Stephen I, the country's first king. Since the year 2000, the iconic crown with the twisted cross on the Hungarian coat of arms, the sceptre, the orb, and the sword in Renaissance style have been on display in a cabinet in the centre of the building.

It serves as a tourist attraction to show visitors what the previous parliament could have looked like.