Munich, Germany

Nine hours is long enough to have a look round central Munich, which is quite small and walkable. Take the S-Bahn from the airport to Marienplatz station, which is in the centre of the historic area. The train takes around fifty minutes as it stops at many locations on the way. Near there is the Viktualienmarkt, where you could get some lunch if the time works.

I'd go into Munich. There are trains about every 10 minutes and it takes 40 to 50 minutes to Marienplatz in front of the Neues Rathaus. 12.40 Eur gets an all-zone day ticket which covers to and from the airport plus any other local transport on U-Bahn, bus or tram.
Assuming your checked luggage is already going to Venice and you have your boarding pass, getting back at the airport 1 hour before the Venice flight should be plenty.

I think Marienplatz is the place you want to go to in Munich. There is an S-Bahn station under Marienplatz. The bus goes to the Hauptbahnhof, so if you take the bus, you'll have to walk to Marienplatz or pay for the S-Bahn to get there. Take the S-Bahn.

There are two S-Bahn going from the airport to Marienplatz. The S1 goes around to the west before coming into town; the S8 comes into town from the east. They leave from opposite sides of the platform at the airport S-Bahn station. Whichever one leaves the airport first gets to Marienplatz first (although the S1 only gets there 2 minutes before the S8), so just take the next one.

On the other hand, if you come back from Marienplatz, take the S8. The S-Bahn in Marienplatz leave from two different levels in the station - the S8 from track (Gleis) 1, the highest level, the S1 from Gleis 2, the next one down. There is a one minute window every 20 minutes when the S1 will get you to the airport 9 minutes sooner, but the other 19 minutes the S1 will take longer. Plus with the S8 you don't have to worry about being on the wrong end of the train and ending up in Freising.

Please explain S-Bahn to the poster. Please don't assume anything. Munich is nice and a short visit to the main part of town will be enjoyable.

The S-Bahn # 8 at Munich airport stops at Munich Hbf (central train station) and then goes to Marienplatz. I would go. Not for 9 hrs would I stay at the airport, easily done on the S-Bahn to get to "city center."

As an alternative, you might consider a 15-20 minute bus or cab ride to Freising. The bus ride is ~ 3 Euros per person.

It has a Baroque Chapel at the Domberg (cathedral on the hill) where the prior Pope was ordained.

It has the world's oldest active brewery.

https://www.weihenstephaner.de/en/our-brewery/

The town is laced waterways and paths. There are several good restaurants and cafes including our favorite, The Wirtshaus Weißbräu Huber.

http://www.weissbraeu-huber.de

If I had a week, I would spend it in Munich. With just one day, we find Freising to be our perfect farewell to Germany.

Please explain S-Bahn to the poster.

Train: a connected line of railroad cars with or without a locomotive (Merriam-Webster dictionary)

The S-Bahn is a type of train.

OK?

For those not familiar with rail travel in Gemany (and I think realistically that encompasses most Americans), there are a number of classes of trains in Germany. The long-distance trains, those that go long distances at high speeds, making few stops, are the Intercity Express (ICE), the Intercity trains (IC), and the EuroCity trains (EC). Regional trains are the Regional Express (RE) that generally go across an individual state, stopping only at major stations, and the slow Regional Bahn trains (RB), milk-run trains that stop at every station. Finally, German Rail runs some commuter trains called S-Bahn or Schnell(fast)-Bahn trains in major cities in Germany. These trains are similar to the Long Island Railroad in our country. They run underground in cities but above ground outside the cities. They are heavy rail cars and often run on lines with full sized trains. They go far out into the suburbs. U-Bahns (underground trains like the Subway) in cities are run by the local metro districts, as are trams and buses. They are lightweight cars and run on their own tracks, usually close to downtown and almost always underground.

Here is a map of the train system in Munich. There are two S-Bahn lines (S1 and S8) that run between the airport and downtown. The U-Bahn does not go out that far. There are a few private bus lines but their schedule is less frequent and the only stop at a few places in town.

If you stick to your plan to go to the city center for which your layover is more than long enough I would recommend contacting the Munich Greeter Group - http://munich-greeter.de/en/ - the local counterpart of the well known Big Apple Greeters in New York. At tour with one of them will be totally tailored to your interest and present you Munich with the eyes of a local. And it will be free of charge!

Great idea to take the S Bahn into Munich. Your all day ticket is good for up to 6 people, so please don't buy a ticket for everyone in your party. Marianplatz has several old churches - St Michael's and St Peter's - also great department stores. Go down to the basement of one of these and you can get a cheap, filling meal at the deli counter. I'll buy a piece of hot schnitzel for a few euros and a bottle of beer/pop and have a great inexpensive meal.

After seeing the Marienplatz you might consider touring the Residenz - the Bavarian Kings' palace. It is very elegant and includes the Bavarian Crown Jewels. Other options would include the English Garden where you can watch surfers, do some walking in treed surroundings or have a beer in a beer garden.

Head to town to see Munich. It is nice, several great ideas above.