Have you ever traveled to a new City when you have only a few hours to spare?
One of your best options would be to join a Guided Tour with a professional Tour Guide that will show you around town and the main places of interest. Well, you can do that and even for FREE (or more accurately – TIP as much as you want), Now they also offer Free Guided Tours with Bikes! (but, you need to bring your own bike or rent a bike in a bike shop yourself).
Here is the Link: http://www.freetoursbyfoot.com/
There is also another company that offers Free Guided Tours in 18 major cities in Europe, the Middle East and the USA (including: Amsterdam, Barcelona, Berlin, Brussels, Copenhagen, Dublin, Edinburg, Hamburg, Jerusalem, Lisbon, Liverpool, London, Madrid, Munich, New York, Paris, Prague and Tel Aviv):