Coworking is a style of work that involves a shared working environment, often an office, and independent activity. Unlike in a typical office environment, those coworking are usually not employed by the same organization. […] Coworking is also the social gathering of a group of people who are still working independently, but who share values, and who are interested in the synergy that can happen from working with like-minded talented people in the same space. Source: Wikipedia » Coworking
Please note that this list is not intended to be complete. I have included only places that I have personally heard of and/or have/had some (limited) contact to people using them. There are far better lists out there that usually get updated more frequently as well (e.g. Coworking.org and their own Wiki).
Including countries outside of the EU as well as ones that are only partially in Europe.
Including countries from the Oceania, the Indian Subcontinent, and the Middle East (but not located in Northern Africa).
Including cities located in the Republic of China (ROC), the People's Republic of China (PRC), or any of their corresponding autonomous regions (e.g. Hong Kong and Macau).