Start your morning with a visit to the Hungarian Parliament Building, a stunning example of Neo-Gothic architecture (45 minutes). In the afternoon, take a stroll through Castle Hill, a UNESCO World Heritage Site, and visit the Matthias Church (2 hours). In the evening, relax in one of Budapest's famous thermal baths, such as the Széchenyi Thermal Baths (2 hours).
In the morning, visit the Schönbrunn Palace, the former summer residence of the Habsburgs (3 hours). In the afternoon, explore the Naschmarkt, Vienna's largest and most popular outdoor market (2 hours). In the evening, attend an opera or ballet performance at the Vienna State Opera (3 hours).
In the morning, take a walking tour of Salzburg's Old Town, a UNESCO World Heritage Site (2 hours). In the afternoon, visit Hohensalzburg Fortress, one of the largest medieval castles in Europe (2 hours). In the evening, attend a classical music concert at the Mozarteum (2 hours).
In the morning, visit Prague Castle, the largest ancient castle in the world (2 hours). In the afternoon, stroll across the Charles Bridge, one of the most famous landmarks in Prague (1 hour). In the evening, enjoy a beer at one of Prague's many local breweries, such as U Fleku (2 hours).
In the morning, visit the Fisherman's Bastion, a unique viewpoint offering stunning views of the city (1 hour). In the afternoon, shop for souvenirs at the Central Market Hall, the largest indoor market in Budapest (2 hours). In the evening, take a Danube river cruise and enjoy the city's beautiful illuminated skyline (2 hours).
If you have extra time, consider taking a day trip from Vienna to the Wachau Valley, a picturesque region known for its vineyards and medieval castles. Another idea is to visit the spa town of Karlovy Vary in the Czech Republic. To maximize your fun, make sure to try some local specialties, such as goulash in Hungary, schnitzel in Austria, and trdelník in the Czech Republic.