Just an hour each way on the train transports you from Vienna's beautifully renovated charm to a somewhat crumbling Bratislava, still emerging from its isolation behind the Iron Curtain.
Although I lived in Bratislava for a year and made frequent day trips to Vienna, I often recommend friends who are flying in and out of Vienna do the reverse and take a day excursion into Bratislava. Since Slovakia joined the European Union in May 2004, this has become even easier now that border formalities are becoming a thing of the past.
Trains headed for Bratislava regularly shuttle between the two cities from Vienna's Südbahnhof (south rail station). It's said that these are the two closest capital cities in the world since Bratislava became the seat of government of the new Slovak Republic following a peaceful split from the Czech Republic in 1993.
My preference is to arrive at the main station, Hlavná Stanica, where a short ride on tram #1 connects to the city center. Other trains terminate in Petralka, a newer station amid a jungle of Soviet-era apartments, and from there bus #90 also goes into the city.
At least for the next few years, Slovakia will lie outside the Euro zone, so it's a good idea to get some Slovak koruna before arriving. Then you can buy a one-day ticket for 90 koruna (US$3.65) and travel anywhere on Bratislava's rickety but widespread public transport service.
Bratislava's Old Town is not as well preserved as those in western parts of Europe, but that's part of the charm. It's near impossible to get lost as following every little alley inevitably leads back to a more familiar square, but it wouldn't hurt to stop at the Tourist Office (Klobuènicka 2) for a town map.
A morning spent rambling through the Old Town should at some stage go past the St Martin Cathedral on the western edge of the main town center. St Martin's visiting hours are a bit hit and miss, but a circumnavigation on foot is just as delightful.
Bratislava Castle (Bratislavský hrad) beamed briefly to the world when Presidents Bush and Putin met there in early 2005. It's more impressive from the outside than in, but it's worth the steep climb up just to see the contrasting views. With one sweeping glance you can gaze over the pretty tiled roofs of the Old Town, the Danube River and on the far shore, the seemingly endless identical blocks of flats where almost a third of Bratislavans live. Various museums are resident in the castle, including the Slovak National Museum (Slovenské národné múzeum).
My favorite spot for a refreshment break depends on the season. In cooler weather, I can't pass by Cokolada (Michalska 6), which offers thirty varieties of hot chocolate mixed with intriguing ingredients, from banana to chili powder.
In warmer weather a multi-scoop ice cream costs under a dollar from one of the many stalls that appear when the temperature rises.
Many eateries in Old Town advertise English menus, and although they tend to charge a little more, they are still good value compared to the Euro-zone and are a good choice when you're on your own and don't speak Slovak.
The popular local dish, bryndzové haluhky, is a concoction of potato dumplings with a sheep cheese sauce, and trying this for lunch is a sure way to impress Slovaks – if you can remember its name, let alone tell them you've eaten it.
On warmer afternoons I'd take the #29 bus from Nový Most to Devín Castle (Hrad Devin). The bus stop is under the bridge near the Hotel Danube at the end of Hviezdoslavovo Square – the opposite end from the Slovak National Theater (Slovenské národné divadlo). Perched on a hill above the Danube and Morava rivers, the castle ruins are a sight enough in themselves, let alone the views back into green Austria.
An invigorating half-day trip, particularly in winter, could be to Kamzík Hill on the suburban edge of Bratislava. Trolleybus #203 from Hodovo Square in front of the presidential palace goes to Koliba, the end of the line. From there it's an uphill walk to a little piece of countryside in the city. In the depths of winter, streams of school kids take plastic sleds to the best spots. Warm up with a coffee or a snack in the TV tower or, if you're a little hungrier, you can try the revolving restaurant with a view over snow-dusted Bratislava, or take an invigorating walk through the snow and forest.
It's a relatively simple matter to head back to the train station and return to Vienna. And if you like your first taste of Slovakia, there's a lot more to see.