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.