Bratislava, Slovakia

Take the train for an hour due east, and you'll find yourself in Bratislava, the capital of Slovakia and one of the prettiest and most well-preserved cities in Europe. 

Bratislava's cobbled pedestrian streets lined with cafes and restaurants, grand old national theatre, and whimsical statues make for an ideal day trip. Even many travelers on tight budgets will find the fare reasonable, and when it's nice out, walking around and visiting the city's main monuments is an inexpensive way to spend the day. 

What to Do There: With its distinctive, brightly colored facades and warm red rooftops, the city is cheerful and full of interesting sites, even on a foggy or rainy day. Make sure to visit the 16th-century Bratislava castle, a storybook-worthy monument that dominates a high hill overlooking the old city. 

If you have a bit more time and wouldn't mind spending a lot of time on the water, a day-long cruise by boat from Vienna to Bratislava is entirely possible, too. However, these cruises generally only operate between April to September.