The typical voltage for households (and hotels) in Vienna is 230 volts (alternating current)
Vienna is potentially one of the safest cities in the world for its size. There are no slums or districts you should avoid. In general, you can visit any part of the city at any time of the day without taking many risks — just use your common sense. At night, though, it is wise to avoid parks. The drug scene at Karlsplatz (underneath the Opera) hangs out there during the day, but they do not care at all about tourists. Just ignore them and they will ignore you. The Prater (fair grounds/amusement park area) is said by some locals to be less safe at night, though more in reference to pickpockets than anything else. As in any major city, watch out for pickpockets who grab and run when boarding the U-Bahn ([‘uːbaːn] subway). Petty crimes (like jackets ‘going missing’) are more common and normally go unreported and won’t get much sympathy. There have been a very few racist assaults in Vienna (even some by the police themselves). One runs the risk of being pickpocketed. Schwedenplatz, along the Ring, is sleazy in the evenings, but basically harmless; the Stadtpark, along the Ring, to the East, is a bit deserted at night and therefore best avoided.
Prostitution is legal, even on the street, and is common around the area of the Prater. Ironically, some of the areas are stones thrown from the UNODC Headquarters (the UN agency responsible for combating human trafficking) and are human trafficking hubs for all of Europe. Many of these prostitutes are not registered and a high number are known to be trafficked, so take care if seeking their services. It is safer for everyone involved to visit a brothel. Women dressed in a certain manner walking around these areas alone at night might feel uncomfortable being checked-out in a certain way but there is no real danger. (There is no male street-prostitution to speak of in Vienna.)
Recently, there have been some reports of fraud around Karlsplatz and the Ring. The usual scenario is that someone will stop you and ask for directions. A couple of other guys show up claiming to be police, showing a badge (must be fake). They ask if you were getting drugs from the other guy and then will ask for your passport and wallet for verification. When you are busy trying to convince them that your passport is valid, one of them sneaks out some money from your wallet. Best to tell them that you want to go to the police station — there is one at Karlsplatz U-Bahnstation. It’s a minor annoyance, but it’s better to be careful. In a different case of fraud they try to convince you that your money is counterfeit money and that they have to inspect it. As always use common sense: police are ought to approach you in a very distinctive way (you will notice if they do so), the badge must have Polizei ([ˌpɔlɪˈʦaɪ̯] police) and the Austrian coat of arms and/or the Austrian flag located somewhere on it, and they will be willing to bring you to the police station or a properly uniformed officer.
Do not walk on the bike lanes and cross them like you would cross any other road. Some bike lanes are hard to recognize (e.g. on the “Ring” in Vienna) and some cyclists bike rather fast. Walking on bike lines is not only considered impolite but it is illegal and you run the danger of getting hit.
If you see people gambling on the streets (usually in popular tourists’ destinations like Stephenplatz or Mariahilferstrasse), stay away! The modus operandi usually involves a guy playing the classic game of “hiding the ball”. This involves covering the ball (or small trinket) with either a bottle cap or a match box and swirling it around with two other bottle caps asking people to guess the position of the ball. The game is set in a way that you can easily see the ball’s position. This is done to lure the unsuspecting person into placing a wager. There are usually two main players and, between them, they will lose and win money back and forth to give the appearance that it is a fair game – do not be tricked! They are from the same gang. Once you get greedy and get lured in, you will surely lose your money! The person in control of the bottle caps will remove the ball from their position through sleight of hand and you will never see your money back. Besides the two or three other players involved, there are usually at least two lookouts – one on each side of ‘stage’. Vienna has plenty of legal casinos if you care to try your luck.
In addition, it is common for suspicious persons to approach you in the city centers if you are standing still for a while (particularly if eating at outdoor tables). They will be holding magazines for sale, and will ask you if you are interested in looking at one for free. They are typically very aggressive in their demeanor. Do not be fooled by them! It is not free. If you look at the magazine for free, they will refuse to take the magazine back and demand payment for it at a high cost (typically 2 euros, which is the price of local homeless’ magazines in Austria like “Augustin“, but they are in German anyways and it indeed has become a trend amongst non-related people to abuse the idea). The best response in this situation is, when they first approach, to simply wave your hands demonstratively to say no while shaking your head and repeat the phrase “Nein danke” ([naɪ̯n ˈdaŋkə] no thank you) to them repeatedly until they leave. If police are nearby, these people may accuse you of stealing the magazine, but many police know of their trickery so stand your ground. However, the best response in all cases is simply to dismiss these beggars by saying “Nein danke” and refusing to take the magazine. They will often look for tourists or people who look as though they are visiting hoping to make a sale; therefore, be prepared to tell them “Nein danke” as necessary so that they will leave you alone. They are not violent and just trying to get money from you, so do not be afraid that they will hurt you if you tell them no.
Vienna’s drinking water is unique in Europe. The majority of Vienna’s water comes from the three “Hochquellwasserleitungen.” Meaning “high-(as in mountain) spring waterlines (as in aqueducts). Indeed the city’s water flows through aqueducts from the mountains around 100 kilometres south of Vienna (Schneeberg and Hochschwab). These were built during the reign of Emperor Franz Josef and supply Vienna with nearly unchlorinated high-quality drinking water, with a considerably higher quality than many bottled waters. So if you visit this city, it is not necessary to buy water, you can drink tap water here – unless you prefer sparkling water.
The telephone prefix for calling Vienna from other countries is: + 43 1
Vienna has a large number of mostly free wireless hotspots in bars, restaurants, and cafés. Wifi is known locally as WLAN or Wireless LAN. Those that are on the Freewave Wi-Fi network freewave.at can be found here:. MuseumsQuartier has free wireless internet.
There are plenty of internet cafes except for in the first district. Touch-screen media terminals are available (including internet) in many phone booths, much of the content about Vienna is free.
If you plan to visit also places outside the city and you don’t want to stay without internet it’s recommended to buy a prepaid 3G-simcard (all providers offer fast 3G service, also in rural and remote areas of Austria) and put it in your smartphone or internet usb stick.
Download is mostly around 5-6 Mbit/sec and upload 2-3 Mbit. (for HSDPA). The monthly cost for mobile internet is between 4 euro (1GB) and 15 euro (unlimited) (August 2011). The best 3G coverage in rural areas is from Three drei.at and A1 a1.at. Vienna is covered very well by HSDPA, HSPA+ and LTE as well.
If you’re a European student you can make use of the eduroam service. The University of Vienna, the Vienna University of Economics and Business Administration, the University of Technology, the Medical University of Vienna, the University of Applied Arts Vienna, the University of Music and Performing Arts as well as the Austrian Academy of Sciences are part of this programme in Vienna.
The usual tip is 10% of the bill. Traditionally the way to tip a waiter is to mention the amount of the bill plus tip when you pay; for instance, if the bill is €15.50 you could give the waiter a €20 note and say “siebzehn (seventeen),” meaning he is to take out €15.50 for the bill, €1.50 for the tip, and so give you only €3 change. In this situation English numbers will usually be understood. Sometimes in less formal restaurants you can alternatively drop the tip into the money pouch the waiter usually carries.
Find info about barrier-free hotels, public transportation, attractions and guides at Wien.info > Accessible Vienna