:-) Your post nicely shows why having a top level domain 'Berlin' could be good idea: without it you would not be able to find those German bike tours. Germany has top level domain de for 'Deutschland'; ge = Georgia (the country)
I was gonna say communities like Catalan speakers (.cat) have a good excuse, but then I remembered that ICANN already gave these people their own TLDs.
It opens new options for "local" addresses: biketour.berlin biketour.paris antics.london etc
wether this will stick is another story.