Budapest is the capital of Hungary. As the largest city of Hungary, it serves as the country's principal political, cultural, commercial, industrial, and transportation centre. In 2010, Budapest had 1,721,556 inhabitants, down from its 1980 peak of 2.06 million. The Budapest Commuter Area is home to 3,271,110 people. The city covers an area of 525 square kilometres (202.7 sq mi) within the city limits. Budapest became a single city occupying both banks of the river Danube with a unification on 17 November 1873 of right (west)-bank Buda and Óbuda with left (east)-bank Pest. Budapest is one of Europe's most delightful and enjoyable cities. Due to its scenic setting and its architecture it is nicknamed "Paris of the East".

Bratislava is the capital of Slovakia and, with a population of about 431,000, also the country's largest city. Bratislava is in southwestern Slovakia on both banks of the Danube River. Bordering Austria and Hungary, it is the only national capital that borders two independent countries. Bratislava and Vienna are two of the closest European national capitals to each other, at less than 37 miles apart. Bratislava is the political, cultural, and economic centre of Slovakia. It is the seat of the Slovak president, the parliament, and the executive branch of the government. It is home to several universities, museums, theatres, galleries and other important cultural and educational institutions.

Vienna is the capital of the Republic of Austria and one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.7 million (2.4 million within the metropolitan area, more than 25% of Austria's population), and is by far the largest city in Austria, as well as its cultural, economic, and political centre. It is the 10th-largest city by population in the European Union. Vienna is host to many major international organizations, such as the United Nations and OPEC. The city is also known for its Imperial palaces, including Schönbrunn, the Habsburgs’ summer residence. Apart from being regarded as the City of Music because of its musical legacy, Vienna is also said to be "The City of Dreams" because it was home to the world's first psycho-analyst – Sigmund Freud.

Salzburg is the fourth-largest city in Austria and the city of the federal state of Salzburg. The city's ''Old Town'' has internationally renowned baroque architecture and one of the best-preserved city centres north of the Alps. It was listed as a UNESCO World Heritage Site in 1997. The city is noted for its Alpine setting. Salzburg was the birthplace of 18th-century composer Wolfgang Amadeus Mozart. In the mid-20th century, the city was the setting for parts of the American musical and film The Sound of Music, which features famous landmarks in Austria. The musical was a partnership between Richard Rodgers and Oscar Hammerstein II. The capital city of the State of Salzburg, the city has three universities.