Wear non-slip shoes. If you see people making sail boats from trash and trying to float them down the river, you will need to speak German to explain why that's a bad idea. Clean up after yourself.
All photos viewed on this website are copyrighted by their owners. Clicking on the author name above will take you to the original page for given photo where you can check the copyright information from the author.
Some photos are provided via Flickr, 500px, Instagram and other open APIs in full compliance with the appropriate Terms & Conditions.