It has a population of around 50,000 people, of whom about 10,000 are students. Passau is situated at the point where the river Inn and the river Ilz meet the Danube (Donau), and for this reason it is often called the "City of Three Rivers" (Dreiflüssestadt). It lies around 2,000 km from the estuary of the Danube on the border to Austria, and enjoys a small but thriving local tourist trade.
The area of Passau was first settled by the Celts, who were living in southern Bavaria since ages before the Romans came and founded a fortress here because of the excellent strategic position of the peninsula of Passau. Later on, the fortress grew and Passau became a real city. Much of the money in the city was made from the salt business with nearby Bohemia (the modern day Czech Republic), with the salt coming from Bad Reichenhall near Salzburg. In the middle ages, Passau's St. Stephen's church was the head of the local church district, which extended all the way to Hungary. Most of the old buildings have survived until today and are in active use.
Nowadays, Passau is known for its historic buildings, its university, and its location at the confluence of the three rivers and the last German train station before entering Austria. Like much of Bavaria, it's also predominantly Catholic. If you look very closely, however, you can spot Protestant churches.
It regularly snows in winter, and it is warm in summer. Quite often you get over 30 degree Celsius during the day.
Most tourists Passau receives are on river cruises going along the Danube, but also many buses arrive here from all over Germany and Austria. Because Passau is not far from the Czech Republic and Austria, you will meet also a lot of Austrians and Czechs going here for shopping or even for working purposes. Most tourists here are native German speakers, though, so don't think you can go everywhere and communicate in English, although you may be surprised how common it is.
Trains regularly pass through Passau. The main railway station (Hauptbahnhof) is in the new city but buses run reguarly to the historic city center or you can walk in 15-20 minutes. You can purchase a Bayern-Ticket which gives you unlimited travel in Bavaria on regional trains (non-express) for a day.
Passau's city is spread out a little, but most places of interest for a tourist are within walking distance. Buses are also common. You can walk 20 minutes from the city center and be in Austria.
You can catch taxis, but they can be a little pricey.
The city buses are cheap and run until 11 p.m. daily.
A wide range of rive trips can be taken from an hour or so to long trips to Austria, that will take several days. If you prefer experiencing the rivers by canoe, there's a company called Sport Eder in the closeby village of Neuhaus where you can rent canoes or book organised canoeing tours.
Passau University is famous in Germany for its Law Degree which has a special focus on English law. Lawyers graduating from Passau are in good stead. Passau's Faculty of Law ranks among the finest in Germany. It also has an excellent international business course, economics course, informatics course, and language courses among others. There's a German as a foreign language course at the university, as well as external pay-for courses.
German students used to receive free tertiary studies until 2007. Now they have to pay 500€ per Semester (1/2 year). Foreign students can study here cheaply also. The catch is that German is a must unless you're taking only German for foreigners subjects.
There's a bunch of tourist shops around Passau, so you can easily find some original Bavarian Lederhosn or Dirndl or a Bavarian hat to take home as a souvenir.
In and around the central shopping mall as well as in close-by Bahnhofstraße you will find the typical highstreet shops like H&M, Orsay, New Yorker and C&A, several shoe shops (Sutor, Görtz 17, Roland), home decoration stores (Butlers, Depot) as well as several book shops. On the first floor of the book shop Pustet there's also a nice little cafe where you can chill out and enjoy a cup of Cappucino whilst having a read.
Passau has quite a lot of restaurants in the city. I don't think I've had a bad meal at any of them yet. You can regularly find some good deals (like Pizza or Pasta + a glass of wine for 5.50€). However, it is much more expensive than eating at home, so locals don't eat out every night.
The Hacklberg Brewery has a nice restaurant full of classic Bavarian dishes that will fatten you up in no time. It also has a great beer garden in the warmer months. To get there you have to cross the Danube and go left, keeping on the second street closest to the Danube.
Passau has five breweries. Every pub or restaurant seems to be associated with one of them. The beer is delicious and cheap.
Like the rest of Germany, buying alcohol out is more expensive than buying it at the supermarket. Service has a big price tag here. The student pubs are almost as cheap as supermarkets, though.
There are a few beer gardens in Passau, and a couple that would pass a "Real Beer Garden test". That means you can bring your own food with you, regardless of whether they sell food themselves or not. Beer gardens developed because breweries used to plant chestnut trees atop their underground cellars (mostly laying a bit outside of the city) to keep them cool, and the result was a really nice atmosphere to relax with a beer in hand. Beer gardens tend to open in the spring and close in the fall as the weather cools again.
Thursdays, Fridays and Saturdays are the nightlife nights. On Thursdays, you have bar-trivia at the Irish Pub Shamrock where your group can win 60€ (or up to 120€ with the jackpot). Questions are in both English and German. The pub is owned by a Welshman, and the employees all speak English as do most of the clientele. The barmen and waitresses come from all across Europe (France, USA, Australia, Poland, you name it) and make fascinating drinking companions.
Close to the Shamrock there's Hossi's Bar, which is a popular small cocktail bar and Cubana, which is always busy on weekends.
Some more drinking spots can be found in the part of town known as Innstadt (an old, picturesque part of town across the river Inn): Colors, Joe's Garage and Bluenotes.
The oldest and probably still most popular club in town is Camera, which is located very centrally in a basement close to Mc Donald's.
Passau is NOT your typical backpacker destination, although backpackers have been known to turn up occasionally. There is only one backpacker-type hostel - the local international youth hostel, located in a castle (Veste Oberhaus) overlooking Passau's city center. It is probably one of the youth hostel with the nicest view you can get in the whole of Central Europe. It's a bit of a climb, but it is apparently quite nice also inside.
There are plenty of Pensions (Bavarian style B&Bs) in and around the city. The Rotel Inn (also known as the "Liegender Mann") is not too expensive (20-25 €/person) and is located close to the railway station.
The only campground in town, Campground Ilzstadt, is located fairly close to the city centre. It is an open field, with no individual plots. Because of the narrow roads no trailers or motorhomes are allowed.
German trains regularly go through Passau to and from Munich, Regensburg and the Austrian cities of Linz and Vienna. There's no shortage of them. Especially if you want to go to Munich, it pays to be at the station a little earlier, as there are usually people looking for travellers who want to share the cost of a Bayern-Ticket (which costs about 30€).