Series 1:

The defense is taking place in the faculty office of the chemistry / pharmacy faculty of Johannes-Gutenberg Universität. I was asked by four professors: my supervisor and professors in analytical chemistry, physical chemistry and microbiology.
First I had to give a 30 mins presentation of the work of my thesis. It took me about 3.5 years of measurements, work with analytical machines (ion chromatography) and analysis and interpretation of the results. Then I was asked about 30 mins about the thesis and after that (this is the worst part) you are asked general questions in chemistry. Certainly after about 4 years focussing on a special field you forgot again all general things about your studies. No photos are taken during the defense. But the fun starts afterwards.
After getting your mark (which was a 'magna cum laude') your colleagues and parents await you outside with champaign.
You may forget all the stress now ... but you have to expect another sort of stress. Since the colleagues play naughty games with you.
First you get your hat in front of the defense room. Afterwards you are taken to the PhD car ... which was a bike in my case.

Series 2:

It's always a lot of work to prepare a doctor-car (I participated several times myself in this job). But it is certainly also a pleasure to ship the poor guy on the car then with a lot of noise over the whole university campus. For me it was on a wonderful and warm day in May and the campus was full with students. Not any embarassing place is let out and so the way goes directly even through the building with the student cafeteria, where students are just scared up during second breakfast or a coffee.

Our University is named after Johannes Gutenberg, who lived in Mainz and invented the book-printing in Europe. There is a statue of him on the compus and there the way goes.

Series 3:

Here all fresh PhDs have to give a speach and to 'baptise' Gutenberg with champaign ...
For this purpose a new bottle was opened and Andreas even managed to catch the flying cork on the photo (see red circle around it on the photo top right).
Please do not ask me what I said there, I cannot remember, but probably it was not very intelligent. ;-)

Series 4:

Back to the docotorla ... hicks ... doctor-car things begin to become a bit dangerous. After this second round of champaign before lunch the colleagues pulling the car tend to become a bit slaphappy and crazy, go in zic-zac and circles with the instable construction and I felt a bit scared worrying to fall down in a sharp curve. Fortunately we have an excellent engineer with years of experience in building doctor-cars. So the bike stood the procedure.
Well, as if the track would not have been fearsome enough, the climax is still coming ... the thing all PhD candidates fear more than the defense itself: THE HORSE.