ATTENTION - 22/06/2020
In the last few weeks I got a lot of emails asking me for the find code of Stage 3 of the adventure lab, as the statue is not approachable due to COVID-19 measures, taken by the university.
The issue has already been addressed earlier by implementing an alterative solution! Please read the description of S3 in the adventure lab carefully to find the alternative solution in case that the statue is not approachable.
If however any problems occur during your walk on the tour, do not hesitate to contact me via email, or the message center!
To find the Bonus Cache, solve the Salzburg City Tour Adventure Lab. You can download the app at here! All further instructions are to be found there!
The tour takes you through the old city core of Salzburg and shows you places, that are quite common, as well as places, that you maybe won't see, when visiting the city normally. On the way you can find many tourist friendly caches that are placed on or near the route of the Adventure Lab Tour. 
Please note the opening hours of Stage 1 and 4 of the Adventure Lab!
Stage 1: April - October: 9-18; November - March 9 -16
Stage 4: Monday - Saturday: 10-17; Sunday 13-17 - Stage 4 is also closed during the rehearsals and shows of JEDERMANN
That's all the information you need. The rest is to be found in the Adventure Lab.
I wish you a lot of fun!
Mannimaker97