CUSTOMISED WALK TOURS for INTROVERTS ► LOGO

My main task was to create a simple and understandable sign.
My client had only one wish - the logotype must consist of the commonly known city Prague silhouette.
Mainly, the logo will be used as a website logo, to decorate gadgets (flash disks, pens and badges), business cards, maps and small leaflets; as well as a handy stencil for marking pavements next to the most interesting areas of Prague.
The city silhouette is a  highly overused element, so I was doing my best to avoid creating another cliché.
In order to add lightness to the design, I decided to keep it in "lines only" - a doodling style.
To express a movement - I add a horizontal "swoosh lines" and because Prague is a city crossed by the meandering Vltava river - I tried to create a logo, which might look a bit similar to a boat (the boat trips are very popular here :o)
And - It is OK if the plug reminds you a happy snake! Do you know of a more introverted creature than a snake... hidden under a medieval city wall? 


Dozens sketches, many tries and errors, various ideas, colours and size mutations... What works OK as a web logo, not always  serves properly as a handy stencil or tiny badge decoration.
Thanks a lot for viewing.
I appreciate any comments or advice
You might have...