Freiburg is a city placed at the crossroads of three countries, and Italy isn't far, not to mention Lichtenstein.
Winters are cold, albeit mostly sunnier than in other parts of Germany. Summer starts relatively early and the city is really pleasant during warmer days. There is a lot to do, much of which you can also do in the winter. The tram (Straßenbahn - "street rail") is easy to use, and this summer all public transportation is free with the 9 Euro monthly pass issued by Deutsche Bahn, the national railway company.
Music concerts and summer festivals
Music and in particular a lot of classical concerts abound all year round. However, in Freiburg, classical concerts at the city's Konzerthaus don't stop over the summer season. I attended a Prokofiev/Rachmaninov concert (Russian conductor, Ukrainian pianist) and a little over a week later, a benefit concert for SOS Children's Villages that involved not only an orchestra, but also a 90-person choir performing Beethoven's 9th Symphony, his best known, thanks to the "Ode to Joy." In this case the proceeds were to finance a scholarship for one young person to attend the UWC Robert Bosch school in Freiburg.
There was a weekend of music all over Freiburg for Gay Pride weekend (June 25), and the summer festival that included a concert with an enormous audience near the main train station, as well as musicians all over town in smaller outdoor venues.
The annual wine festival took up much of the Münsterplatz for almost a week beginning of July. The local vineyards set up tents and served their wine, and there were food stalls too. The local Baden region wine is very good; one of my favorites is the red` "Spätburgunder" (late Burgundy), often very smooth.
2. Dip your toes in the river
The Dreisam River flows through Freiburg and is easily accessible. It's shallow and on hot summer weekends, every single stone in the river may be occupied by a human in a swimsuit! On other days, there will be less of a crowd. You can also just decide to sit in the Tageszeitung Biergarten (the extensive menu looks like a newspaper), watch the river, and have a drink or a meal (bizarrely, you have to wait until 1:30 pm to be able to order food. I'm not sure why, and whether this is only on Sundays).
3. Swim at Seepark, or just enjoy the park
Seepark is easy to reach via the 3 or 4 tram. It is a large city park, anchored by a lake. If you don't want to swim, you can sit in the Japanese Garden, enjoying the fountains and the peaceful layout. You can have a drink or lunch at one of the cafes. Climb up a tower or two and look down at the city. Watch swans, coots and ducks. Join a presentation on dragon- and damselflies at a small pond. And if you do swim, you'll have ducks passing a foot away from you, totally ignoring you. In July it's baby season, and ducklings are unafraid; swans bring their little one to the shore to see if there aren't any tidbits to eat.
4. Visit museums
Freiburg is not a world capital, but it is no slouch in the museum department. There are several for which you can buy a day pass for 8 euros, and visit as many as you like in one day (they're not that big). I visited the Augustiner Museum twice, the Museum of Modern Art, the Museum for Natural History, and the Historical Museum. All were fascinating. The Augustinermuseum is mainly specialized in local religious art: gargoyles, sculptures, paintings, stained glass... but currently has an exhibition about Freiburg's place in German colonial history.
5. Stroll around the Vauban neighborhood
For a taste of the more "funky" Freiburg, take the 3 tram to see a neighborhood known for its sustainable practices. There are few cars outside of the main road (residents who own a car are supposed to acquire a parking spot in the neighborhood garage), no street parking, plants galore including fruit trees, and I heard about a unicycle--although I only saw regular bicycles (Freiburg, the "Bicycle Capital of Germany," supposedly has the most bicycles per capita in all of Germany). I read that Vauban (named after the French Marshal who built fortifications in Freiburg when the city was under French occupation in the 17th Century) used to be a military base and then was occupied by squatters who refused to leave. They finally were able to acquire some of the old military barracks, and other parts of the neighborhood were organized into sections that were bought by a variety of groups: some architect-led, some everyday citizens, a few developers. Some people live in converted containers or vehicles. A wood-chip burning power station supplies heat to the neighborhood. You can find additional information at Sights of Vauban (in 4 languages).
6. Climb up Schlossberg (or take the cable car part of the way up)
If you're reasonably fit, you can hike up the Schlossberg (a little over a mile) and enjoy a panoramic view of Freiburg. If you don't suffer from vertigo, you can also go up the tower built right on top (which I did not attempt. It sways with the wind). The castle itself is in ruins and I didn't even see it. There used to be fortifications, but they were destroyed during one of the many occupations of Freiburg. The cable car goes part of the way up, ending at a nice restaurant. You still need to climb a while to get to the top. On the way down is an old-fashioned drinking water station (photo below left).